Some bullets, called tracer and API bullets, contain a pyrotechnical charge. The charge in the bottom of a tracer bullet burns in flight and enables the shooter or an observer to see the bullet's trajectory. An Armor Piercing Incendiary (API) bullet contains a hard core and a pyrotechnical charge that …

tract Micro wind turbines can be structurally integrated on top of the solid base of noise barriers near highways. A number of performance factors were assessed with holistic experiments in wind tunnel and in the field. The wind turbines underperformed when exposed in yawed flow conditions. The theoretical …