Orthodontic Appliances: Types, Uses, and Effects
Center of Resistance in Orthodontics
- Center of Resistance: The point on the tooth where, if a single force is applied, it would result in the tooth’s translation along the line of action of that force.
Factors Affecting the Center of Resistance
- Number of roots
- Degree of alveolar bone loss
- Degree of root resorption
Anchorage in Orthodontics
Anchorage: The resistance to unwanted tooth movement.
Absolute Anchorage: Appliances gaining anchorage from extraoral structures.
Example: Titanium screws implanted into
Read MoreVehicle Wheel and Tire Characteristics
Main Characteristics
- Pavement: Dampens irregularities encountered by a vehicle wheel.
- Functions: Bear vehicle weight, transmit power, secure the wheel, and facilitate braking.
Rim and Tire Terminology
The rim is the metal part of the wheel that supports the tire. It connects to the vehicle’s hub.
Types of Rims:
- Deep Base Rim: One-piece rim with a deep center for easy tire mounting and removal. Features inclined seats.
- Removable Wheels:
- Semi-Deep: Less deep with a removable base for tab assembly.
- Flat Base
Magnetic Fields and Materials: Properties and Applications
Magnetic Hysteresis
Magnetic hysteresis occurs when a ferromagnetic material is subjected to a changing magnetic field. As the external field increases and then decreases to zero, the magnetization of the material follows a different path, forming a loop. This loop represents the energy lost due to hysteresis.
Action of a Magnetic Field on a Current
When a conductor carrying an electric current is placed within a magnetic field, a voltage is induced across the conductor’s ends, and a force acts upon
Read MoreUnderstanding Diodes: Types, Function, and Applications
Diodes: An Introduction
A diode (Greek: two roads) is a semiconductor device that allows the passage of electric current in one direction, with characteristics similar to a switch. In simple terms, the characteristic of a diode (IV) consists of two regions: below a certain potential difference, it behaves like an open circuit (no leads), and above it as a closed circuit with a very small electrical resistance.
Because of this behavior, diodes are often referred to as rectifiers. They are devices that
Read MoreCapacitors: Understanding Electrical Energy Storage
Capacitors
In electricity and electronics, a capacitor is a device that stores electrical energy, a passive component. It consists of a pair of conductive surfaces positioned to influence each other totally (that is, all electric field lines that start from one go to the other). These surfaces are usually in the form of tables, fields, or plates, separated by a dielectric material (used in a capacitor to reduce the electric field because it acts as an insulator) or by a vacuum. Following a difference
Read MoreCar Suspension Systems: Components and Types
Parts of the Suspension
The suspension system is composed of several key components:
- Spring action system: Springs, leaf springs, torsion bars, pneumatic ball systems.
- Damping of oscillations: Shock absorbers (buffers).
Dynamics of Suspension
- Roll center: An imaginary point at which lateral forces acting on the wheels are transmitted to resist the action of centrifugal force.
- Center of gravity: The imaginary point where all the mass of the vehicle is located, and where both terrestrial gravity and dynamic