Condiciones Laborales y de Salud de Los Trabajadores de la Maquila del Tabaco. Ciudad El Paraíso, Honduras. Octubre 2003 a Marzo 2004.

El propósito es describir las características socio demográficas, las condiciones de trabajo y situación de salud de los trabajadores para aportar información y conocer la magnitud y trascendencia de esta problemática y tomar decisiones necesarias de prevención

The drag coefficient of sand particles as a function of the Reynolds number.

<p>The relationship of the drag coefficient of sand grains of different shape to the Reynolds number is shown. Here, the black solid line indicates spherical sand grains, and are two different ellipsoid-shaped sand particles, represents cube-shaped sand particles, and represent two types of cylinder-shaped sand particles, and represents frustum-shaped sand particles.</p

The sand transport rate per width for sand particles of different shape.

<p>(a). Comparison of calculated sand transport rates per width for different shapes sand particles with equivalent diameters of with experimental data. (b). Comparison of calculated sand transport rates per width for sand particles of different shape with equivalent diameters of with experimental data. The black solid line indicates spherical sand grains, and are two different ellipsoid-shaped sand particles, represents cube-shaped sand particles, and are two types of cylinder-shaped sand particles, and represents frustum-shaped sand particles.</p

Parameters of sand particles with different shapes.

<p>where and are two different ellipsoid-shaped sand particles, represents cube-shaped sand particles, and represent two types of cylinder-shaped sand particles, and represents frustum-shaped sand particles.</p><p>Parameters of sand particles with different shapes.</p

The sand transport rates of sand particles with different shapes as a function of height.

<p>(a) and (b) show the sand transport rates of sand particles with the same equivalent diameter of as a function of height but at different friction wind velocities. (c), (d) and (e) represent the sand transport rates of sand particles with the same equivalent diameter of as a function of height but at different friction wind velocities. Here, the black solid line indicates the spherical sand grains, and are two different ellipsoid-shaped sand particles, represents cube-shaped sand particles, and are two types of cylinder-shaped sand particles, and represents frustum-shaped sand particles.</p

The drag force of different shaped particles with height.

<p>All the sand particles of different shapes take off with the same horizontal initial velocity of and vertical initial velocity of . The black solid line indicates spherical sand grains, and are two different ellipsoid-shaped sand particles, represents cube-shaped sand particles, and are two types of cylinder-shaped sand particles, and represents frustum-shaped sand particles.</p

Deployment-based lifetime optimization for linear wireless sensor networks considering both retransmission and discrete power control

<div><p>A sophisticated method for node deployment can efficiently reduce the energy consumption of a Wireless Sensor Network (WSN) and prolong the corresponding network lifetime. Pioneers have proposed many node deployment based lifetime optimization methods for WSNs, however, the retransmission mechanism and the discrete power control strategy, which are widely used in practice and have large effect on the network energy consumption, are often neglected and assumed as a continuous one, respectively, in the previous studies. In this paper, both retransmission and discrete power control are considered together, and a more realistic energy-consumption-based network lifetime model for linear WSNs is provided. Using this model, we then propose a generic deployment-based optimization model that maximizes network lifetime under coverage, connectivity and transmission rate success constraints. The more accurate lifetime evaluation conduces to a longer optimal network lifetime in the realistic situation. To illustrate the effectiveness of our method, both one-tiered and two-tiered uniformly and non-uniformly distributed linear WSNs are optimized in our case studies, and the comparisons between our optimal results and those based on relatively inaccurate lifetime evaluation show the advantage of our method when investigating WSN lifetime optimization problems.</p></div

Parameters for the SNs.

<p>Parameters for the SNs.</p

Transmission power and range for Mica2 (<i>f</i> = 868 MHz, <i>α</i> = 3.95).

<p>Transmission power and range for Mica2 (<i>f</i> = 868 MHz, <i>α</i> = 3.95).</p

Data transmitted and received at Node <i>N</i>_<i>y</i>.

<p>Note: and represent the next hop and the last hop of Node <i>N</i>_<i>y</i>, respectively.</p