Variation in the thickness of a fluid interface due to internal wave propagation:a lattice Boltzmann simulation

The change in the thickness of an interface between two immiscible fluids due to the propagation of an internal capillary-gravity wave along the interface is considered using a Bhatnagar, Gross and Krook (BGK) lattice Boltzmann model of a binary of fluid. The vertical thickness of the interface is recorded from the simulations since this is the most easily measured quantities in any simulation or experiment. The vertical thickness is then related to the actual thickness (perpendicular to the interface) which is seen to vary with the phase of the wave. The positions of the maxima and minimum thicknesses are seen to be approximately constant relative to the phase of the propagating wave and the range of variation of the thickness decreases at approximately the same rate as the wave amplitude is damped. A simplified model for the interface is considered which predicts a similar variation due to the interface being stretched as the internal wave propagates

An Electromagnetic Calculation of Ionospheric Conductance that seems to Override the Field Line Integrated Conductivity

We derive a steady-state, electromagnetic solution for collisional plasma and apply it to computing the total conductance for a vertically stratified ionosphere interrogated by a 3D signal with finite transverse wavelength, which we compare to the field-line-integrated conductivity, finding significant differences on all scales investigated. The approximate solution is derived from an exact linearization of the electromagnetic 5-moment fluid equations, and writing down the integral form of the driven steady-state solution, which is expressed as a sum over modal contributions associated with the eigenvectors/eigenvalues of the set of equations. We find the eigenvectors/eigenvalues numerically and use them to argue that only two of the modes are capable of transmitting energy through the ionosphere. Approximating their integrands with analytic functions yields a solution valid for homogeneous plasma, expressed in terms of the eigenvectors/eigenvalues for the two modes. The solution may be understood using wavepacket concepts. Transmission line theory is then used to extend the homogeneous-plasma solution to a solution for the vertically-stratified ionosphere. We review how transmission line theory contains electrostatic theory as a special case, and show that our solution reproduces electrostatic theory exactly when the eigenvectors/eigenvalues have the right properties, which requires that they be artificially modified. Otherwise we find short-wavelength, mode-mixing, and wave-admittance effects with broad relevance to ionospheric science, and to global modeling of the Sun-Earth system. Since resonant systems can be very sensitive, quantitative accuracy may require tuning, but the physical conclusions seem unavoidable and to affect all transverse scales.Comment: 50 pages including 8 figure pages. Supplementary Information includes 10 anonymous peer reviews with detailed replies, accumulated from earlier version

Passenger Car Equivalents of Light Duty Trucks and the Costs of Mixed Vehicle Traffic: Evidence from Michigan

This study uses naturalistic data from drivers operating instrumented vehicles to estimate the following distance by vehicle type and compute the passenger car equivalents of light duty trucks (LDTs). Unlike most previous studies, this study separates LDTs by vehicle type and produces evidence that cars follow different types of LDTs at different distances. While car drivers follow pickup trucks more closely, they follow SUVs and minivans at a greater distance. The external cost on the transportation system is estimated to be approximately $37 million annually in the Detroit area and$2.05 billion annually for the United States as a whole

Constructing Integrable Third Order Systems:The Gambier Approach

We present a systematic construction of integrable third order systems based on the coupling of an integrable second order equation and a Riccati equation. This approach is the extension of the Gambier method that led to the equation that bears his name. Our study is carried through for both continuous and discrete systems. In both cases the investigation is based on the study of the singularities of the system (the Painlev\'e method for ODE's and the singularity confinement method for mappings).Comment: 14 pages, TEX FIL

Ultra-low-cost logging anemometer for wind power generation feasibility surveys

We describe the design and implementation of a cup anemometer capable of logging average wind speed, maximum wind speed and seconds with wind above a criterion speed, on individual weeks. The instrument will operate for at least 54 weeks on two AA dry cells. The intention is that this instrument be deployed to ascertain whether it would be economical to install a wind generator, at a fraction of the cost of a multipurpose weather data logging station. It is designed around a $2 microcontroller that provides non-volatile memory. Provision has been made for using either a magnetic reed switch or the motor from a discarded hard disk drive to sense rotation. The latter enables the use of an otherwise worthless bearing and drive assembly to provide an especially frugal solution

Gender-Specific Marketing Strategies Used by Sports Supplements: A Descriptive Study

While the use of sports supplements is common among athletes and active adults, the marketing strategies used by these sports supplement manufacturers remain unknown—especially relative to active and athletic women. This descriptive study aims to describe marketing strategies used, such as color choices, structure function claims, and picture choice, and analyze if there are gender-specific differences within the strategies. A total of 100 best-selling sports supplements were selected from three separate third-party websites. Food products, accessories, and kitchen appliances were excluded. Supplement main webpages and sports supplement-specific webpages were explored to determine which marketing strategies were used and if there were gender-specific differences. Of 169 sports supplement webpages reviewed, only 23.1% (n=39) included pictures that were only/majority female. Only 7.1% (n=12) of supplement bottles used feminine colors, while for supplement pages, only 8.3% (n=14) utilized feminine colors and 43.2% (n=73) used masculine colors. While the number of women athletes continues to grow, sports supplement manufacturers are not using strategies targeted to women. Future research should examine the reasons for this discrepancy and women’s perceptions of purchasing sports supplements targeted to men

Cibenzoline for treatment of ventricular arrhythmias: A double-blind placebo-controlled study

Cibenzoline, a new class I antiarrhythmic drug, was administered to 24 patients with frequent (> 30/h) premature ventricular complexes. Three patients discontinued the medication because of epigastric distress before repeat ambulatory electrocardiography. Of the remaining 21 patients, 13 responded to 130 mg twice daily by more than 75% suppression of premature ventricular complex frequency and 6 additional patients responded to 160 mg twice daily during an open-label titration phase. Events of ventricular tachycardia (≥3 beats) were totally suppressed in 9 of 10 patients and markedly diminished in the 1 remaining patient. During a doubleblind placebo-controlled crossover phase in 16 patients (21 patients minus 2 nonresponders and 3 who developed side effects), cibenzoline suppressed the number of premature ventricular complexes per 24 hours (4,075 ± 868 to 1,758 ± 1,089, p = 0.02), the number of events of ventricular tachycardia (31 ± 30 to 2 ± 0, p = 0.01) and the number of premature ventricular complex pairs (61 ± 28 to 25 ± 21, p = 0.01). Cibenzoline plasma concentration was 59 to 421 ng/ml in responders and higher (387,758 and 852 ng/ml, respectively) in the three subjects with side effects (right bundle branch block in one, hypotension in one, gastrointestinal upset and central nervous system complaints in one). Cibenzoline plasma concentration correlated with PR interval (r = 0.55, p = 0.0106) and corrected QT interval (r = 0.58, p = 0.0054). Further clinical investigation of this new antiarrhythmic agent is needed

Species Preference Influences on Cattle Grazing Behaviour

Lotus corniculatus offers specific nutritional benefits to animals, but exploiting these advantages in grazing systems depends on the proportion of lotus in the feed offered and the animals\u27 preference, hence desire to select for it. To determine preference for lotus, heifers were offered free-choice in contrasting, spatially separated but adjacent monocultures of ryegrass-lotus or red clover-lotus. Following a one-week period to adjust to the species offered and their arrangement, 10 young heifers were observed at 10-minute intervals during daylight hours, and the species they were on and whether or not they were grazing was recorded. This procedure was conducted in summer (February) and autumn (May). Partial preference was determined from the proportion of time spent grazing each species. Preference for lotus was higher when the alternative species was ryegrass, than when it was red clover, in both summer (75:25 vs 53:47) and autumn (67:33 vs 54:46), although this preference for lotus in the ryegrass-lotus contrast reduced in autumn compared with that exhibited in summer. Total grazing time, which was similar for each contrast, was lower in autumn (6 hrs) than in summer (9 hrs). For the ryegrass-lotus contrast, the reduced grazing time in autumn resulted from reduced time grazing lotus, whereas on the red clover-lotus contrast they reduced grazing time equally on both species