A mesoscopic model for microscale hydrodynamics and interfacial phenomena: Slip, films, and contact angle hysteresis

We present a model based on the lattice Boltzmann equation that is suitable for the simulation of dynamic wetting. The model is capable of exhibiting fundamental interfacial phenomena such as weak adsorption of fluid on the solid substrate and the presence of a thin surface film within which a disjoining pressure acts. Dynamics in this surface film, tightly coupled with hydrodynamics in the fluid bulk, determine macroscopic properties of primary interest: the hydrodynamic slip; the equilibrium contact angle; and the static and dynamic hysteresis of the contact angles. The pseudo- potentials employed for fluid-solid interactions are composed of a repulsive core and an attractive tail that can be independently adjusted. This enables effective modification of the functional form of the disjoining pressure so that one can vary the static and dynamic hysteresis on surfaces that exhibit the same equilibrium contact angle. The modeled solid-fluid interface is diffuse, represented by a wall probability function which ultimately controls the momentum exchange between solid and fluid phases. This approach allows us to effectively vary the slip length for a given wettability (i.e. the static contact angle) of the solid substrate

A coexisting anatomic variation of median and ulnar nerves in a cadaver palm

During a routine dissection we observed an anatomical variation of the median nerve and an atypical anastomosis in the palm region of a male cadaver. There were four distinct recurrent motor branches of the left median nerve and the palmar cutaneous branch of the ulnar nerve communicated directly with the third common palmar digital nerve. The presence of such anatomical variant in the hand should keep surgeons alert in the management of hand pathology especially in carpal tunnel syndrome which is a routine operation for many medical centers

Hydroelastic analysis of ice shelves under long wave excitation

Abstract. The transient hydroelastic response of an ice shelf under long wave excitation is analysed by means of the finite element method. The simple model, presented in this work, is used for the simulation of the generated kinematic and stress fields in an ice shelf, when the latter interacts with a tsunami wave. The ice shelf, being of large length compared to its thickness, is modelled as an elastic Euler-Bernoulli beam, constrained at the grounding line. The hydrodynamic field is represented by the linearised shallow water equations. The numerical solution is based on the development of a special hydroelastic finite element for the system of governing of equations. Motivated by the 2011 Sulzberger Ice Shelf (SIS) calving event and its correlation with the Honshu Tsunami, the SIS stable configuration is studied. The extreme values of the bending moment distribution in both space and time are examined. Finally, the location of these extrema is investigated for different values of ice shelf thickness and tsunami wave length

A correlative study of Quantitative EMG and biopsy findings in 31 patients with myopathies

A direct correlation of QEMG with muscle biopsy findings might help delineate the sensitivity of QEMG in identifying muscle pathology as well as provide information on electrophysiological- histological correlations. In a study of 31 patients with a variety of myopathies we found that the sensitivity of QEMG was between 24 to 69% depending of the specific method of signal analysis. The positive predictive value of abnormal QEMG was more than 90% while its negative predictive value was only about 20%. Amplitude outlier analysis was superior especially in minimally weak muscles (MRC > 4) and was particularly sensitive at detecting increased variability in fiber size and more subtle myopathic changes

Proton conductivity and luminiscence properties of lanthanide aminotriphosphonates

Metal phosphonates are multifunctional solids with tunable properties, such as internal H-bond networks, and high chemical and thermal stability [1]. In the present work, we describe the synthesis, structural characterization, luminescent properties and proton conduction performance of a new family of isostructural cationic compounds with general formula [Ln(H4NMP)(H2O)2]Cl·2H2O [Ln = La3+, Pr3+, Sm3+, Gd3+, Tb3+, Dy3+, Ho3+, H6NMP = nitrilotris(methylphosphonic acid)]. These solids are formed by positively charge layers, which consist of isolated LnO8 polyhedra and bridge chelating NMP2- ligands, held apart by chloride ions and water molecules. This arrangement result in extended interlayer hydrogen networks with possible proton transfer pathways. The proton conductivity of Gd3+ sample, selected as prototype of the series, was measured. In the range between range 25º and 80 ºC, the conductivity increase with the temperature up to a maximum value of 3.10-4 S·cm-1, at relative humidity of 95 %. The activation energy obtained from the Arrhenius plot (Figure 1) is in the range corresponding to a Grotthuss transfer mechanism.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. FQM-1656; MAT2013-41836-R

Propagation of acoustic-gravity waves in inhomogeneous ocean environment based on modal expansions and HP-FEM

A coupled mode model is presented for the propagation of acoustic-gravity waves in layered ocean waveguides. The analysis extends previous work for acoustic waves in inhomogeneous environment. The coupled mode system is derived by means of a variational principle in conjunction with local mode series expansion, obtained by utilizing eigenfunction systems defined in the vertical section. These are obtained through the solution of vertical eigenvalue problems formulated along the waveguide. A crucial factor is the inclusion of additional modes accounting for the effects of spatialy varying boundaries and interfaces. This enhancement provides an implicit summation for the slowly convergent part of the localmode series, rendering the series rapidly convergent, increasing substantialy the efficiency of the method. Particular aspects of the method include high order Lagrange Finite Element Methods for the solution of local vertical eigenvalue problems in the case of multilayered waveguides, and Gauss-type quadrature for the computation of the coupled-mode system coefficients. The above aspects make the present method quite efficient for long range propagation in extended waveguides, such as the ones found in geophysical applications, e.g. ocean basins, as only few modes are needed for the accurate representation of the wave field