We study the Riemann problem with forward combustion due to injection of air into a porous medium containing solid fuel. We neglect air compressibility and heat loss to the rock formation. Given initial reservoir and injection conditions, we prove that there is a unique time asymptotic wave sequence for combustion with complete oxygen consumption. The sequence consists of a region of unburned a...

In this study we compare the relative merits of Z-cut and X-cut lithium niobate (LN) electrooptic modulators. The finite element method (FEM) has been used to implement a full wave analysis of the two structures and determine the microwave effective index Nm, the characteristic impedance Zc, the microwave losses αc and the half wave voltage VπL, operating at frequency range from 0.1 to 100GHz. ...

SPECTRAL RETRIEVALS USING WAM MODEL AND BUOY DATA P. Heimbach, S. Hasselmann, K. Hasselmann and M. Toporek Max-Planck-Institut f ur Meteorologie, Bundesstra e 55, D-20146 Hamburg, Germany Phon: + 49 / 40 / 4 11 73 3 77, Facs: + 49 / 40 / 4 11 73 2 98 E-mail: [email protected] Abstract A global statistical intercomparison was carried out for the period January 1993 to December 1995 between wave ...

This study assessed healthy young adults to determine the normal limits for electrocardiographic variables and cut-off values for left ventricular hypertrophy. It was a cross sectional descriptive study in which the participants were evaluated clinically by standard 12-lead resting electrocardiogram (ECG) at 25 mm/s during quiet respiration. The heart rate, P wave duration, axis and amplitude, ...

A plane acoustic wave propagating through a high sound speed gradient layer in a liquid near a pressure-release surface is considered in detail. Analogously to the solution for the refraction of the incident plane wave obtained previously, equations describing the refraction of the reflected wave are derived. For the total acoustic field in the layer, dependencies of the pressure and the vertic...

Background: Atrial fibrillation (AF) is the most common arrhythmia in patients with β-thalassemia major (β-TM) due to cardiac iron overload. AF may be predicted by changes in P wave parameters. The aim of this study was to evaluate the correlation between P-wave parameters and atrial markers with mean serum ferritin levels measured yearly. Methods: Fifty patients with β-TM and 50 healthy subje...

The dynamics of a one-dimensional slowly modulated, nearly monochromatic localized wave train in deep water is described by a one-dimensional soliton solution of a twodimensional nonlinear Schrödinger (NLS) equation. In this paper, the instability of such a wave train with respect to transverse perturbations is examined numerically in the context of the NLS equation, using Hill’s method. A vari...

The aim of this study was to assess the effect of filtering techniques on the time-domain analysis of the ECG. Multi-lead ECG recordings obtained from chronic atrial fibrillation (AF) patients after successful external cardioversion have been acquired. Several high-pass filtering techniques and three cut-off frequency values were used: Bessel and Butterworth four-pole and two-pole bidirectional...