Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are fully or partly halogenated paraffin hydrocarbons that contain only carbon (C), hydrogen (H), chlorine (Cl), and fluorine (F), produced as volatile derivatives of methane, ethane, and propane. They are also commonly known by the DuPont brand name Freon.

Bacillus Calmette-Guerin (BCG) vaccine is a vaccine primarily used against tuberculosis (TB). It is named after its inventors Albert Calmette and Camille Guerin. In countries where TB or leprosy is common, one dose is recommended in healthy babies as soon after birth as possible. In areas where TB is not common, only children at high risk are typically immunized, while suspected cases of TB are individually tested for and treated.

Atomic weight is the relative weight of the atom on the basis of oxygen as 16. For a pure isotope, the atomic weight rounded off to the nearest integer gives the total number of neutrons and protons making up the atomic nucleus. These weights expressed in grams are called gram atomic weights.

Atomic fluorescence spectrometry (AFS) is an analytical method used to determine the concentration of elements in samples. The sample is converted to gaseous atoms, and the element of interest is excited to a higher electronic energy level by a light source.

Atomic absorption spectroscopy (AAS) and atomic emission spectroscopy (AES) is a spectroanalytical procedure for the quantitative determination of chemical elements using the absorption of optical radiation (light) by free atoms in the gaseous state. Atomic absorption spectroscopy is based on absorption of light by free metallic ions.

Frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. The technology is used in telecommunications, radio broadcasting, signal processing, and computing.

DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person's body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mt DNA).

Dichlorodiphenyltrichloroethane, commonly known as DDT, is a colorless, tasteless, and almost odorless crystalline chemical compound, an organochloride. Originally developed as an insecticide, it became infamous for its environmental impacts. DDT was first synthesized in 1874 by the Austrian chemist Othmar Zeidler.

CNG (Compressed Natural Gas) is a mixture of hydrocarbons consisting of approximately 80 to 90 % methane in gaseous form. Because of its low energy density, it is compressed to pressure of 200 to 250 Kg/cm2 (to enhance the vehicle on-board storage in a cylinder), hence the name Compressed Natural Gas.

Closed-circuit television (CCTV), also known as video surveillance, is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted, though it may employ point-to-point (P2P), point-to-multipoint (P2MP), or mesh wired or wireless links. Even though almost all video cameras fit this definition, the term is most often applied to those used for surveillance in areas that require additional security or ongoing monitoring.

LORAN, short for long range navigation, was a hyperbolic radio navigation system developed in the United States during World War II. It was similar to the UK's Gee system but operated at lower frequencies in order to provide an improved range up to 1,500 miles with an accuracy of tens of miles.

Liquefied petroleum gas (LPG, LP gas, or condensate), is a flammable mixture of hydrocarbon gases such as propane and butane.

LPG is used as fuel gas in heating appliances, cooking equipment, and vehicles. It is increasingly used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce damage to the ozone layer. When specifically used as a vehicle fuel it is often referred to as autogas.

In electromagnetism and electronics, electromotive force (EMF) is the electrical action produced by a non-electrical source. Devices provide an emf by converting other forms of energy into electrical energy, such as batteries or generators. Sometimes an analogy to water pressure is used to describe electromotive force.

High Frequency is a popular skincare technique that is used to treat a variety of conditions, including acne management, enlarged pores, fine lines and wrinkles, and puffy or dark eyes.

Gold is a chemical element with the symbol Au (from Latin: aurum) and atomic number 79, making it one of the higher atomic number elements that occur naturally. In a pure form, it is a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions.

Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid (DNA) are nucleic acids. Along with lipids, proteins, and carbohydrates, nucleic acids constitute one of the four major macromolecules essential for all known forms of life.

Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around 20 kHz to around 300 GHz. This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies; these are the frequencies at which energy from an oscillating current can radiate off a conductor into space as radio waves.

Radar (Radio Detection and Ranging) is a detection system that uses radio waves to determine the distance (range), angle, or velocity of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the object(s).

Polyvinyl Chloride (PVC or Vinyl) is a high strength thermoplastic material widely used in applications, such as pipes, medical devices, wire and cable insulation, the list is endless. It is the world's third-most widely produced synthetic plastic polymer.

Medium frequency (MF) is the designation for radio frequencies (RF) in the range of 300 kilohertz (kHz) to 3 megahertz (MHz). Part of this band is the medium wave (MW) AM broadcast band. The MF band is also known as the hectometer band as the wavelengths range from ten to one hectometer (1000 to 100 m).