Precision velocity measurements in ultrasonic inspection.

Electromagnetic - acoustic transducer (EMAT) generate ultrasound in the material being investigated. When a wire or coil is placed near to the surface of an electrically conducting object and is driven by a current at the desired ultrasonic frequency, eddy currents will be induced in a near surface region. If a static magnetic field is also present, these currents will experience Lorentz forces of the form F=J x B
Where F is a body force per unit volume, J is the induced dynamic current density, and B is the static magnetic induction. The most important application of EMATs has been in nondestructive evaluation (NDE)applications such as flaw detection or material property characterization. Couplant free transduction allows operation without contact at elevated temperatures and in remote locations. The coil and magnet structure can also be designed to excite complex wave patterns and polarizations that would be difficult to realize with fluid coupled piezoelectric probes. In the inference of material properties from precise velocity or attenuation measurements, use of EMATs can eliminate errors associated with couplant variation, particularly in contact measurements.

what is a computer ?

A computer is an electronic device that can process, store, retrieve, and transmit data. It can perform various tasks and instructions based on the software installed in it. The computer consists of hardware components like the central processing unit (CPU), memory, hard drive, monitor, keyboard, and mouse and software components like operating system, applications, and programs. The computer has revolutionized the way we work, learn, communicate, and entertain ourselves, making our lives more convenient and productive.

The basic parts without which a computer cannot work are.

1)  Central Processing Unit (CPU): It is the brain of the computer that performs all the calculations and instructions

2)  Random Access Memory (RAM): It is a temporary memory that stores the data and instructions for the CPU to access quickly.

3) Storage: It is a device that stores data permanently, such as a hard drive or solid-state drive.

4) Motherboard: It is the main circuit board that connects all the components of the computer.

5) Power Supply Unit (PSU): It provides power to all the components in the computer.

6)  Graphics Processing Unit (GPU): It is responsible for the display of images and videos on the computer monitor

7)  Input and Output Devices: These include a keyboard, mouse, monitor, and speakers that allow users to input data and receive output from the computer

.All these components need to work together to ensure the proper functioning of a computer.