El ciclo del nitrógeno (The Nitrogen Cycle)

Why do some things heat up quickly while others don't? How can heat cause matter to change form from solid to liquid to gas and back again? Heat cannot be seen, but it can easily be felt. Looking at different objects' molecular makeup, this book describes the fundamentals of heat and furthers understanding through a series of easy experiments.

Stephen F. Austin grew up to become known as the Father of Texas. Readers can learn about his interesting and incredible life in this appealing biography that has been translated into Spanish and highlights both Austin's life and Texas history. Through vivid images and illustrations, supportive text, an accommodating glossary and index, and fascinating facts, readers will learn about Texas pioneers, the empresario system, Freemasons, and how Austin became such an important figure in Texas history. This 6-Pack includes six copies of this title and a lesson plan.

Defines screws, explains their functions, and suggests simple experiments to demonstrate how they work.

Se desarrolla, paso a paso, el calculo de 26 problemas de navegacion astronomica, ortodromica y cinematica naval para el interesado en situarse durante la navegacion oceanica mediante las referencias que ofrecen para ello los astros del firmamento. Sin duda la "navegacion a la antigua" debe ofrecer al interesado diversion y entretenimiento y no ser una tecnica cotidiana de navegacion, pues para ello se ejecuta en la actualidad una sofisticada navegacion instrumental.Se corresponde el contenido del libro con el temario actual de las asignaturas de calculo y navegacion para aquellos marinos que ...