CHEMISTRY GLOSSARY

radiant power    →   snaga radijacije

Radiant power is energy of radiation striking a unit area per unit time. The SI unit of radiant power is J m^-2 s^-1.

horse power    →   konjska snaga

Horse power is an obsolete non-SI of power introduced by James Watt in 1782 to allow describing the power of steam machinery. It was equal to the work effort of a horse needed to raise vertically 528 cubic feet of water to one metre in one minute (HP = 735.498750 W).

power    →   snaga

Power is the rate at which work is done. If a force does work W in a time interval Δt, the average power is:

Instantanous power is the instantaneous rate of doing work:

Like work, power is scalar quantity. Its SI unit is watt (W); 1 W=1 J s^-1.

microwave radiation    →   mikrovalna radijacija

Microwave radiation is a electromagnetic radiation with wavelength between 3 mm and 30 cm.

radiation    →   radijacija

The process of heat transfer which occurs through empty space and can also occur in matter, in the form of electro-magnetic (EM) waves, is called radiation or radiant heat. Whenever EM radiation is emitted and then absorbed, heat is transferred. This principle is used in microwave ovens, laser cutting, and RF hair removal.

radiation damage    →   radijacijsko oštećenje

Radiation damage is a general term for the alteration of properties of a material arising from exposure to ionising radiation (penetrating radiation), such as X-rays, γ-rays, neutrons, heavy-particle radiation, or fission fragments in the nuclear fuel material.

adrenaline    →   adrenalin

Adrenaline was the first naturally produced hormone to be isolated in its pure state. It is known as epinephrine, but its chemical name is 1-[3,4-dihydroxyphenol]-2-methylaminoethanol. Adrenaline is a hormone, produced by the medulla of the adrenal glands, that increases heart activity, improves the power and prolongs the action of muscles, and increases the rate and depth of breathing to prepare the body for "fright, flight, or fight". At the same time it inhibits digestion and excretion.

Beer’s law    →   Beerov zakon

Beer’s law (or Beer-Lambert law) is the functional relationship between the quantity measured in an absorption method (A) and the quantity sought, the analyte concentration (c). As a consequence of interactions between the photons and absorbing particles, the power of the beam is attenuated from P_o to P. Beer’s law can be written

where A is the absorbance at a given wavelength of light, ε is the molar absorbtivity or extinction coefficient (L mol^-1 cm^-1), unique to each molecule and varying with wavelength, b is the length of light path through the sample (cm), and c is the concentration of the compound in solution (mol L^-1).

Bragg angle    →   Braggov kut

Bragg angle (Θ) is the angle between an incident X-ray beam and a set of crystal planes for which the secondary radiation displays maximum intensity as a result of constructive interference. British physicist Sir William Henry Bragg and his son Sir William Lawrence Bragg developed a simple relation for scattering angles, now call Bragg’s law.

which relates the angle θ between a crystal plane and the diffracted X-ray beam, the wavelength λ of the x-rays, the crystal plane spacing d, and the diffraction order n (any integer).

The diffraction experiment as presently considered is intended to provide quantitative information on the lattice constant and shape characteristics of the unit cell.

decibel    →   decibel

Decibel (db) is a unit of sound intensity level, or sound power level, defined by equation relating sound intensities or sound power to reference level.