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The practical problem consists in measuring flow rates or flow speeds efficiently. Ideally, one would like to measure the flow rate accurately while affecting the flow as little as possible, generating very little extra pressure drop and flow disturbances while keeping to simple measuring devices. Sharp-edged orifice metres are the most common instruments used for flow rate measurement (about 50 % of the market). This is mainly because they are simple mechanical devices, easy to manufacture and without any moving part. However, they are rather energy inefficient. They consist in a circular hole drilled on a thin plate. The plate is then inserted into the pipe to create a pressure drop from which a mean flow-rate-based velocity can be deduced. An alternative, more efficient approach would be to redesign the circular orifice to control the flow. Here, we proposed to replace the ‘classical circular orifice’ by a fractal-based orifice. We found significant improvements with the fractal pattern. The main results are that the pressure loss which is the direct cost of the flowmeter is decreased by around 10 % with some fractal designs while the pressure drop across the orifice that is actually used for the measurement is barely affected.

An anisotropic solution adaptive method based on unstructured quadrilat- eral meshes for inviscid compressible flows is proposed. The data structure, the di- rectional refinement and coarsening, including the method for initializing the refined new cells, for the anisotropic adaptive method are described. It provides efficient high resolution of flow features, which are aligned with the original quadrilateral mesh structures. Five different cases are provided to show that it could be used to resolve the anisotropic flow features and be applied to model the complex geometry as well as to keep a relative high order of accuracy on an efficient anisotropic mesh. AMS subject classifications: 51E12, 65M08, 68U05, 68U20

A One Health approach is critical to strengthening health security at country, regional, and global levels. However, operationally its uptake remains limited. Recent momentum in assessing capacity to effectively prevent, detect, and respond to disease threats has resulted in identification of gaps that require dedicated action. This article highlights relevant tools, standards, and guidance to assist countries and institutions in meeting the collective vision articulated at the 2018 Prince Mahidol Award Conference on "Making the World Safe from the Threats of Emerging Infectious Diseases." Taking stock of assessment findings, resources, priorities, and implementation initiatives across human and animal health, environment and disaster risk reduction sectors can help expand participation in global health security, target risk drivers, and form synergies for collective action and shared gains for both emerging and endemic disease challenges. In addition to health security gains, a multisectoral, One Health approach can drive benefits for wider health sector and global development goals.

Swirling flows in conical pipe can be found in a number of industrial processes, such as hydrocylone, separator and rotating machinery. It has been found that wall oscillations can reduce the drag in water channel and pipe flows, but there is no study of a swirling flow combined with a vibrating wall in conical pipes, though there are many applications of such combination in engineering processes. A two-dimensional particle image velocimetry (PIV) is used to measure the swirling flow field in a water conical pipe subjected to a periodic vibrating wall for a Reynolds number 3800. The flow velocity statistics are studied under different vibration frequencies corresponding to Strouhal numbers from 60 to 242. The instantaneous axial and vertical velocity in one vibrating period, the mean velocities, and Reynolds stresses were obtained. The results show the existence of an intermediary recirculation cell in the middle of the pipe. They also show that the vibration improves the symmetry for the swirling flow while decreasing dramatically the velocity fluctuation., Comment: 11 pages, 7 figures

Fractal-shaped orifices are thought to have a significant effect on the flow mixing properties downstream a pipe owing to their edge self-similarity shape. Here, we investigate the pressure drop after such fractal orifices and measure the pressure recovery at different stations downstream the orifice. A direct comparison is made with the pressure drop measured after regular circular orifices with the same flow area. Our results show that the fractal-shaped orifices have a significant effect on the pressure drop. Furthermore, the pressure drop measured across the fractal-shaped orifices is found to be lower than that from regular circular orifices of the same flow areas. This result could be important in designing piping systems from the point of view of losses. It looks promising to use the fractal-shaped orifices as flowmeters as they can sense the pressure drop across them accurately with lower losses than the regular circular-shaped ones.

Direct oxidation borohydride fuel cells are very attractive energy conversion devices. Silver has been reported as one of the few materials which can catalyze an 8-electron oxidation. Potential step amperometric pulse techniques to synthesize nanostructured silver material on flat glassy carbon electrodes is reported and significant differences with bulk silver deposit have been observed. The oxidation of borohydride ion on the silver particles occurs at -0.025 V vs. SCE and the potential decreases towards negative values at longer cycle times. The oxidation current also decreases with the number of cycles, suggesting that the silver active sites become partially blocked by oxidation products of borohydride. The electroactive area per unit electrode area of silver was relatively low for particles deposited using potential step amperometric techniques on glassy carbon (0.002 cm2 per cm-2) compared with the area found at a polycrystalline silver electrode (0.103 cm2 per cm-2).

The development of redox flow cells has been carried out through the use of several redox couples which oxidize and reduce to store electrical energy. Some problems encountered in redox cells include: low solubility of redox couples, slow kinetics, low stability of electrode materials and high toxicity of electroactive species. In this paper, Co(III)/Co(II) has been investigated as a possible electroactive material because of its high oxidizing power and the relatively low toxicity of Co(III). The electrochemical study of Co(III)/Co(II) was carried out on different electrode materials such as glassy carbon, Au, Pt, Pb and stainless steel. Results show that the high oxidizing power of Co(III) does not enable to observe its reduction reaction in the aforementioned electrode materials possibly due to electrode surface corrosion and/or water oxidation. However, the electrolysis of Co(III) with a Pb electrode shows that the system is reversible and forms PbO2 on the electrode surface

It has been argued in [10] that due to the lack of sweeping of small scales by largescales in kinematic simulation, the validity of the Richardson's power law might be affected.Here, we argue that the discrepancies between the authors on the ability of kinematicsimulation, KS, to predict Richardson power law may be linked to the inertial subrange theyhave used. For small inertial subrange, KS is efficient and the significance of the sweepingcan be ignored, as a result we limit the KS agreement with the Richardson scaling law t3 forinertial subrange kN/k1 ≤ 10000. Above this value, the sweeping effect of the small scales bythe large scales must be taken in considerations where KS failed to reproduces this power lawin that range as obtained in [13].

Transport and deposition of aerosol particles in a plane channel with a ribbed wall are studied in order to investigate the effects of the turbulent flow structure on particle deposition. In this paper, kinematic simulation (KS) has been adapted to be a sub-grid model for particles, in conjunction with large eddy simulation (LES) in real space with boundaries. KS is a Lagrangian model of turbulent dispersion that takes into account the effects of spatio-temporal flow structure on particle dispersion. It is a unified Lagrangian model of one-, two- and indeed multi-particle turbulent dispersion and can easily be used as a Lagrangian sub-grid model for LES codes, thus enabling complex geometry to be taken into account. To study the effect of small-scale flow structures on particle deposition in the ribbed channel flow, we use a validated LES code to simulate the flow field, and KS to model the sub-grid flow structures. Thus, the large scales are resolved by the simulation and the small scales are modelled using various sub-grid models. As none of the existing sub-grid models is known to have taken into account the effects of small-scale turbulent flow structures on particle deposition, it is important to use KS's ability to remodel the sub-grid velocity field and thereby incorporate its effect on particle deposition. The parameters of our simulations for LES are the Reynolds number, width of the channel, height of the rib and sub-gridmodel parameters. For KS, the parameters are the energy dissipation rate obtained from LES, the energy spectra, ratio of the largest and smallest sub-grid scales and the total number of modes for the sub-grid velocity field. The turbulent flow features thus obtained are compared with published experimental data in a ribbed channel. Our results suggest that while the small-scale (sub-grid) turbulent flow structures have negligible effects on particles with large relaxation times (compared with the Kolmogorov dissipation time scale), deposition of the particles with small relaxation times in the ribbed channel can be affected by these sub-grids.

The properties of one-particle and particle-pair diffusion in rotating and stratified turbulence are studied by applying the rapid distortion theory (RDT) to a kinematic simulation (KS) of the Boussinesq equation with a Coriolis term. Scalings for one- and two-particle horizontal and vertical diffusions in purely rotating turbulence are proposed for small Rossby numbers. Particular attention is given to the locality-in-scale hypothesis for two-particle diffusion in purely rotating turbulence both in the horizontal and the vertical directions. It is observed that both rotation and stratification decrease the pair diffusivity and improve the validity of the locality-in-scale hypothesis. In the case of stratification the range of scales over which the locality-in-scale hypothesis is observed is increased. It is found that rotation decreases the diffusion in the horizontal direction as well as, though to a much lesser extent, in the vertical direction.

The aim of this paper is to deduce a discrete version of the fractional Laplacian in matrix form defined on the 1D periodic (cyclically closed) linear chain of finite length.We obtain explicit expressions for this fractional Laplacianmatrix and deduce also its periodic continuum limit kernel. The continuum limit kernel gives an exact expression for the fractional Laplacian (Riesz fractional derivative) on the finite periodic string.In this approach we introduce two material parameters, the particle mass $\mu$ anda frequency $\Omega\_{\alpha}$. The requirement of finiteness of the the total mass and total elastic energy in the continuum limit (lattice constant $h\rightarrow 0$) leads to scaling relations for the two parameters, namely$\mu \sim h$ and $\Omega\_{\alpha}^2\sim h^{-\alpha}$.The present approach can be generalized to define lattice fractional calculus on periodic lattices in full analogy to the usual `continuous' fractional calculus., Comment: arXiv admin note: text overlap with arXiv:1412.5904

Among K2P channels, a few of them turned out to be difficult to express in heterologous systems and were coined "silent subunits". Recent studies have shed light on the mechanisms behind this apparent lack of channel activity at the plasma membrane. For TWIK1 and THIK2 channels, silence is related to a combination of intracellular retention and low intrinsic activity. TWIK1 is constitutively endocytosed from the plasma membrane before being transported to recycling endosomes, whereas THIK2 is restricted to endoplasmic reticulum. These intracellular localizations are related to trafficking signals located in the cytoplasmic parts of the channels. When these motifs are mutated or masked, channels are redistributed at the plasma membrane and produce measurable currents. However, these currents are of modest amplitude. This weak basal activity is due to a hydrophobic barrier in the deep pore that limits water and ions in the conduction pathway. Other silent channels KCNK7, TWIK2, and TASK5 are still under study. Expression and characterization of these K2P channels pave the way for a better understanding of the mechanisms controlling intracellular trafficking of membrane proteins, ion conduction, and channel gating.

Einleitung: Die Frühgeburt bringt ein gesteigertes Risiko einer konnatalen Hörstörung mit sich. Der Kontrolle der Hörfunktion muss daher bei allen Frühgeborenen besondere Aufmerksamkeit zuteilwerden. In der vorgestellten Arbeit wird untersucht, inwieweit die aktuellen Erkenntnisse hinsichtlich Prävalenz, Diagnostik, Therapie und Risikofaktoren von Hörstörungen bei Frühgeborenen praktische Anwendung finden. Methoden: Die Behandlungsdaten von 128 in der HNO-Universitätsklinik Magdeburg während der Jahre 2006 bis 2011 pädaudiologisch untersuchten Frühgeborenen wurden ausgewertet. Die zusätzliche Analyse aller Screeningdaten (n=67.640) aus diesem Zeitraum ermöglichte Rückschlüsse auf die Prävalenz von Hörstörungen bei Frühgeborenen in Sachsen-Anhalt. Ergebnisse: Fast alle Frühgeborene erhalten ein Hörscreening. Die Auswertung zeigt jedoch, dass die Umsetzung im Detail oft nicht den in der G-BA-Richtlinie definierten Qualitätszielen entspricht. Beispielsweise erfolgt keine regelhafte Anwendung der in Risikogruppen empfohlenen Screeningmethode (AABR) oder der richtliniengemäße Screening- und Therapiezeitpunkt wird nicht eingehalten. Die Prävalenz angeborener Hörstörungen steigt annähernd exponentiell mit abnehmendem Gestationsalter. Schlussfolgerungen: Die Verlaufsevaluation der Umsetzung des Neugeborenenhörscreenings wurde bereits bei Einführung des Programmes geplant. Im Rahmen dieser aktuell laufenden Studie sollte der praktischen Versorgung von Risikogruppen besondere Beachtung gewidmet werden, um auf Basis der erhobenen Daten die (Screening-) Diagnostik und Therapie strukturiert zu optimieren. Unabhängig von der Geburtsklinik sollte gleichermaßen die Chance auf rechtzeitige Diagnostik und damit auf frühzeitige, prognostisch günstigere Therapie einer Hörstörung bestehen. Der Erstautor gibt keinen Interessenkonflikt an., GMS Current Posters in Otorhinolaryngology - Head and Neck Surgery; 11:Doc305; ISSN 1865-1038

We use kinematic simulation (KS) to study the development of a material line immersed in a three-dimensional turbulent flow. We generalize this study to a material surface, cube and sphere. We find that the fractal dimension of the surface can be explained by the same mechanism as that proposed by Villermaux & Gagne (Phys. Rev. Lett. vol. 73, 1994, p. 252) for the line. The fractal dimension of the line or the surface is a linear function of time up to times of the order of the smallest characteristic time of turbulence (or Kolmogorov timescale). For volume objects we describe the respective role of the Reynolds number and of the object's characteristic size. Using the method of characteristics with KS we compute the evolution with time of a concentration field and measure the fractal dimension of the intersection of this scalar field with a given plane. For these objects, we retrieve the result of Villermaux & Innocenti (J. Fluid Mech. vol. 393, 1999, p. 123) that the Reynolds number does not affect the development of the fractal dimension of the iso-scalar surface and extend this result to volume geometries. We also find that for volume objects the characteristic time of development of the fractal dimension is the large scales' characteristic time and not the Kolmogorov timescale.

A three-dimensional kinematic simulation (KS) model is used to study one- and two-particle diffusion in turbulent flows. The energy spectrum E(k) takes a power law form E(k)∼k−p. The value of this power p is varied from 1.2 to 3, so that its effects on the diffusion of one and two particles can be studied. The two-particle diffusion behaves differently depending on whether the two-particle separation is larger or smaller than the smallest scale of turbulence (Kolmogorov length scale η). When the two-particle mean square separation 〈Δ2(t)〉 is smaller than η2 it experiences a time exponential growth 〈Δ2(t)〉=Δ02eγ(t/tη) but for a very short time. For longer times, when η2

Three different approaches are used for evaluating some Lagrangian properties of homogeneous turbulence containing anisotropy due to the application of a stable stratification and a solid-body rotation. The two external frequencies are the magnitude of the system vorticity 2Q, chosen vertical here, and the Brunt-Vaisala frequency N, which gives the strength of the vertical stratification. Analytical results are derived using linear theory for the Eulerian velocity correlations (single-point, two-time) in the vertical and the horizontal directions, and Lagrangian ones are assumed to be equivalent, in agreement with an additional Corrsin assumption used by Kaneda. They are compared with results from the kinematic simulation model (KS) by Nicolleau & Vassilicos, which also incorporates the wave-vortex dynamics inherited from linear theory, and directly yields Lagrangian correlations as well as Eulerian ones. Finally, results from direct numerical simulations (DNS) are obtained and compared for the rotation-dominant case B = 2Ω/N = 10, the stratification-dominant case B = 1/10, the non-dispersive case B = 1, and pure stratification B = 0 and pure rotation N = 0

T M Michelitsch, B A Collet, A P Riascos,A F Nowakowski and F C G A Nicolleau,J. Phys. A: Math. Theor. 50 (2017) 055003, doi:10.1088/1751-8121/aa5173; International audience; We analyze time-discrete and continuous `fractional' random walks on undirected regular networks with special focus on cubic periodic lattices in $n=1,2,3,..$ dimensions.The fractional random walk dynamics is governed by a master equation involving {\it fractional powers of Laplacian matrices $L^{\frac{\alpha}{2}}$}where $\alpha=2$ recovers the normal walk.First we demonstrate thatthe interval $0

International audience; The 1D discrete fractional Laplacian operator on a cyclically closed (periodic) linear chain with finite number $N$ of identical particles is introduced. We suggest a ''fractional elastic harmonic potential", and obtain the $N$-periodic fractional Laplacian operator in the form of a power law matrix function for the finite chain ($N$ arbitrary not necessarily large) in explicit form. In the limiting case $N\rightarrow \infty$ this fractional Laplacian matrix recovers the fractional Laplacian matrix of the infinite chain.The lattice model contains two free material constants, the particle mass $\mu$ and a frequency $\Omega_{\alpha}$.The ''periodic string continuum limit" of the fractional lattice model is analyzed where lattice constant $h\rightarrow 0$ and length $L=Nh$ of the chain (''string") is kept finite: Assuming finiteness of the total mass and total elastic energy of the chain in the continuum limit leads to asymptotic scaling behavior for $h\rightarrow 0$ of the two material constants, namely $\mu \sim h$ and $\Omega_{\alpha}^2 \sim h^{-\alpha}$. In this way we obtain the $L$-periodic fractional Laplacian (Riesz fractional derivative) kernel in explicit form. This $L$-periodic fractional Laplacian kernel recovers for $L\rightarrow\infty$ the well known 1D infinite space fractional Laplacian (Riesz fractional derivative) kernel. When the scaling exponent of the Laplacian takes integers, the fractional Laplacian kernel recovers, respectively, $L$-periodic and infinite space (localized) distributional representations of integer-order Laplacians.The results of this paper appear to be useful for the analysis of fractional finite domain problems for instance in anomalous diffusion (Levy flights), fractional Quantum Mechanics, and the development of fractional discrete calculus on finite lattices.

Despite a high level of sequence homology, tandem pore domain halothane-inhibited K(+) channel 1 (THIK1) produces background K(+) currents, whereas THIK2 is silent. This lack of activity is due to a unique combination of intracellular retention and weak basal activity in the plasma membrane. Here, we designed THIK subunits containing dominant negative mutations (THIK1(DN) and THIK2(DN)). THIK2(DN) mutant inhibits THIK1 currents, whereas THIK1(DN) inhibits an activated form of THIK2 (THIK2-A155P-I158D). In situ proximity ligation assays and Förster/fluorescence resonance energy transfer (FRET) experiments support a physical association between THIK1 and THIK2. Next, we expressed covalent tandems of THIK proteins to obtain expression of pure heterodimers. Td-THIK1-THIK2 (where Td indicates tandem) produces K(+) currents of amplitude similar to Td-THIK1-THIK1 but with a noticeable difference in the current kinetics. Unlike Td-THIK2-THIK2 that is mainly detected in the endoplasmic reticulum, Td-THIK1-THIK2 distributes at the plasma membrane, indicating that THIK1 can mask the endoplasmic reticulum retention/retrieval motif of THIK2. Kinetics and unitary conductance of Td-THIK1-THIK2 are intermediate between THIK1 and THIK2. Altogether, these results show that THIK1 and THIK2 form active heteromeric channels, further expanding the known repertoire of K(+) channels.