Definition: Translate the given Spanish text to English

Positive Example 1 -
Input: A method for converting a series of m-bit information words to a modulated signal is described.
Output: Se describe un método para convertir una serie de palabras de informacion de bits m a una señal modulada.

Positive Example 2 -
Input: A last plastic cover is applied as a final protection.
Output: La presente invencion comprende un nuevo mezclador termocinetico.

Negative Example 1 -
Input: Luminescent optical sensor.
Output: SENSOR OPTICO LUMINISCENTE.

Negative Example 2 -
Input: The urinal is similar to a common toilet.
Output: El común es similar a un inodoro orinal.

Now complete the following example -
Input: The test tube has an original design, which may have two recesses: the first recess is located at the central portion of the tube, the same being sharper where the fatigue resistance of the material is measured; the second recess being optional, thus may be located at the free end portion of the test tube where a load pre-evaluated by numerical simulation is located.
Output: El diseño de la probeta es un diseño original que puede presentar dos depresiones: una en la parte central siempre presente y más pronunciada donde se mide la resistencia a la fatiga del material; la segunda, no siempre presente, en el extremo libre de la probeta donde se puede colocar una carga preevaluada mediante simulación numérica.