An Ultrasonic Pest Repeller is an electronic device that uses ultrasonic sound waves to repel insects, rodents, and other pests. Though humans are incapable of hearing these sounds, many animals, insects, and rodents can. There is much debate concerning the ultrasonic pest repeller’s ability to actually get rid of pests. While some people claim that …
What was once only a dream has now become a reality as space travel is a regular activity in our society. With thousands of satellites in orbit, the Hubble Space Telescope that can see other galaxies, regular shuttle launches, and prototypes for vehicles that can fly in and out of the atmosphere, it makes sense …
An earthquake is caused when two blocks or plates of the Earth slip past each other in the lateral, vertical, or a combination of directions in a sudden manner. Due to the large pressures that develop between the Earth’s plates along fault lines at the Earth’s surface, one of the bodies will eventually give way. …
Vibration measurements are made in order to identify when preventive or corrective repairs are required on machinery. These repairs are made in order to reduce or eliminate the noise that damaged equipment make. This prevents catastrophic failure of the equipment. Vibration measurements are frequently made on process control equipment and rotating machinery such as the …
Specific gravity is a special case of relative density. That is, a substance’s density is divided by the density of water at 4 F (0 C). Since water has a density of 1 gram/cm3 and all of the units cancel, specific gravity is the same number as density, but without any units (dimensionless). Relative density …
Total Harmonic Distortion (THD) is a measured difference in audio levels between the input audio signal’s harmonics and the harmonics of the output audio signal of an amplifier or other audio device. Output Distortion Level As the signal passes through an amplifier it is always somewhat distorted at its output. The waveform at the input …
Backscatter X-ray machines were built specifically for airport security. Backscatter X-ray technology can strip off a person’s clothing in the captured image to show him or her practically naked. In the process, it will show any contraband such as ceramic knives, liquid explosives or drugs that the person was carrying but were previously undetectable by …
The Boltzmann Constant (Boltzmann’s Constant) is a fundamental physics constant that plays a pivotal role in almost every single statistical formulation in both quantum and classical physics. It is named after Austrian physicist, Ludwig Boltzmann (1844 – 1906), who made significant contributions to the foundation and development of a particular branch of theoretical physics known …
FTIR spectroscopy (Fourier Transform Infrared Spectroscopy) is a technique that uses infrared light to observe properties of a solid, liquid, or gas. It is used in many different applications to measure the absorption, emission, and photo-conductivity of matter by shining a narrow beam of infrared light at the matter in various wavelengths and detecting how …
A permanent magnet (ferromagnet) is a material that produces a magnetic field. Permanent magnets are made from ferromagnetic materials, such as iron, and are created when the material is placed inside of a magnetic field. When the magnetic field is removed, the object remains magnetized. Permanent magnets have a permanent magnetic field and do not …