Your tonsils are gland-like structures in the back of your throat. You have one located in a pocket on each side. Tonsils are made of tissue that contains lymphocytes -- cells in your body that prevent and fight infections.onsil stones, or tonsilloliths, are formed when this trapped debris hardens, or calcifies. This tends to happen most often in people who have chronic inflammation in their tonsils or repeated bouts of tonsillitis.
A self-centering chuck, also known as a scroll chuck, uses dogs (usually called jaws), interconnected via a scroll gear (scroll plate), to hold onto a tool or workpiece.
A Self Erecting Tower Crane (SETC) is a Tower Crane that can be easily inserted on a site with restricted space in a short period of time. These cranes operate from a fixed position and must be safely placed on site by qualified field engineers familiar with the mechanisms that they are using. A Self Erecting Tower Cranes is normally operated using a crane remote control, though in some cases an operator cab may be fitted to the tower section.