- Day
- (noun) Duration of 24 hours.
- Daytime
- (noun) Time interval between sunrise and sunset.
- Decantation
- (n.) The process of allowing a mixture to settle. Using gravitational force, the densest substances settle at the bottom of the container, while the least dense substances rise to the surface.
- Density
- (n.) The ratio of the mass of a certain volume of a material to the mass of the same volume of pure water at 4°C. At this temperature, the mass of one liter of water is equal to 1,000 grams.
- Derived Branch
- (n.m.) Portion of a circuit with derivations that goes from one node to the next and does not contain the generator.
- Diffused Light
- (n.f.) Light reflected in all directions by an illuminated object.
- Diffusing Medium
- (n.) A portion of space containing particles that scatter light in all directions. Smoke, dust, and fog are examples of diffusing media.
- Diffusing Object
- (n.) An illuminated object that reflects light in all directions. It is said to diffuse light.
- Dinitrogen
- (n.) A colorless, odorless, and tasteless gas with the formula N2. The melting point of dinitrogen is -209.86°C. Its boiling point is -195.8°C. Its density under normal conditions is 1.2506 g/L. It was named by the chemist A. Lavoisier, who noted that respiration, and thus life, is impossible in an atmosphere of dinitrogen. It constitutes approximately four-fifths of the air by volume. Pure dinitrogen is obtained by the distillation of air and is used to create an inert chemical atmosphere and for the preparation of ammonia, ammonium salts, nitric acid, urea, and nitrogen fertilizers.
- Diode
- (n.) A two-terminal device that allows current to pass in only one direction and indicates the conventional direction of the current.
- Dioxygen
- (n.) A colorless, odorless, and tasteless gas with the formula O2. The melting point of dioxygen is -218.8°C. Its boiling point is -182.96°C. It constitutes approximately one-fifth of the air by volume. In liquid or solid form, it has a bluish color. Dioxygen is mainly used in steelmaking for steel production, in the manufacture of nitric acid, explosives, and various other chemicals, in the refining of oils and fats, and in wastewater treatment. Compressed in cylinders, it is used in all artificial aeration devices for high-altitude aircraft, submersibles, and diving suits. In liquid form, mixed with combustible substances, it is used as a propellant in rockets. It has numerous therapeutic applications, such as in cases of anoxia and hyperbaric oxygenation.
- Dipole
- (n.) An electrical component that has two terminals (two connection points).
- Direct Voltage
- (n.) Voltage that remains constant over time.
- Disordered State
- (n.) A state of matter where molecules are not arranged in a regular manner, particularly when molecules can move.
- Dispersed State
- (n.) A state of matter where molecules are far apart and separated by empty space.
- Dissolution
- (n.) The dispersion of a substance in a liquid.
- Dissolved Gas
- (n.m.) Gas contained in a liquid with which it forms a homogeneous mixture.
- Distance
- (n.) A physical quantity that is measured with a ruler. Its legal unit is the meter (symbol: m).
- Distillate
- (n.) A liquid obtained by distillation that has undergone boiling followed by condensation.
- Distillation
- (n.) A method for separating the components of a homogeneous mixture through vaporization followed by condensation.
- Divergent Lens
- (n.f.) Lens that is thicker at the edge than at the center.
- Divergent Light Beam
- (n.) A beam of light that spreads out. The luminous energy disperses.
- Duralumin
- (n.) (trademark) An alloy of aluminum and copper, containing small amounts of magnesium, manganese, and silicon. It is lightweight, hard, and resistant to breakage. Also known as Dural.
- Duration
- (n.) A time interval. Its legal unit is the second (s).
- Dynamometer
- (n.) An instrument for measuring the weight of an object.