spectrum

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spectrum

 [spek´trum] (L.)
1. the series of images resulting from the refraction of electromagnetic radiation (e.g., light, x-rays) and their arrangement according to frequency or wavelength.
2. range of activity, as of an antibiotic, or of manifestations, as of a disease. adj., adj spec´tral.
absorption spectrum one obtained by passing radiation with a continuous spectrum through a selectively absorbing medium.
broad-spectrum effective against a wide range of microorganisms.
visible spectrum that portion of the range of wavelengths of electromagnetic vibrations (from 770 to 390 nanometers) which is capable of stimulating specialized sense organs and is perceptible as light.

spec·trum

, pl.

spec·tra

,

spec·trums

(spek'trŭm, -ă, -ŭmz),
1. The range of colors presented when white light is resolved into its constituent colors by being passed through a prism or through a diffraction grating: red, orange, yellow, green, blue, indigo, and violet, arranged in increasing frequency of vibration or decreasing wavelength.
2. Figuratively, the range of pathogenic microorganisms against which an antibiotic or other antibacterial agent is active.
3. The plot of intensity versus wavelength of light emitted or absorbed by a substance, usually characteristic of the substance and used in qualitative and quantitative analysis.
4. The range of wavelengths presented when a beam of radiant energy is subjected to dispersion and focused.
[L. an image, fr. specio, to look at]

spectrum

(spĕk′trəm)
n. pl. spec·tra (-trə) or spec·trums
1. Physics
a. The entire range over which some measurable property of a physical system or phenomenon can vary, such as the frequency of sound, the wavelength of electromagnetic radiation, or the mass of specific kinds of particles.
b. A specific portion of such a range: the infrared spectrum.
c. A characteristic distribution of phenomena manifested over such a range: the emission spectrum for sodium vapor.
d. A graphic representation of such a distribution; a spectrogram.
e. A band of colors produced when the wavelengths making up white light are separated, as when light passes through a prism or strikes drops of water.
2.
a. A range of values of a quantity or set of related quantities: the income spectrum.
b. A sequence or range of related qualities, ideas, activities, entities, or phenomena: the whole spectrum of 20th-century thought; the spectrum of genes involved in the immune response.

spec·trum

, pl. spectrums, spectra (spek'trŭm, -trŭmz, -tră)
1. The range of colors presented when white light is resolved into its constituent colors by being passed through a prism or through a diffraction grating: red, orange, yellow, green, blue, indigo, and violet, arranged in increasing frequency of vibration or decreasing wavelength.
2. The range of pathogenic microorganisms against which an antibiotic or other antibacterial agent is active.
3. The plot of intensity versus wavelength of light emitted or absorbed by a substance, usually characteristic of the substance and used in qualitative and quantitative analysis.
4. The range of wavelengths presented when a beam of radiant energy is subjected to dispersion and focused.
[L. an image, fr. specio, to look at]

spectrum 

1. Spatial display of a complex radiation produced by separation of its monochromatic components.
2. Composition of a complex radiation, e.g. continuous spectrum, line spectrum (CIE). Plural: spectra. See light.
absorption spectrum The curve representing the relative absorption of a pigment or chemical substance as a function of the wavelength of light. Example: the absorption spectrum of rhodopsin. Syn. absorbance spectrum.
action spectrum A graphical representation of the relative energy necessary to produce a constant biological effect. Example: frequency of action potentials in a ganglion cell as a function of wavelength.
continuous spectrum A spectrum in which, over a considerable range, all wavelengths exist without any abrupt variation in intensity. Example: the spectrum of hot solids. See filament lamp.
electromagnetic spectrum The total range of all electromagnetic waves. It extends from the longest radio waves of some thousands of metres in wavelength through radar, microwave, infrared rays, visible rays (between wavelengths 780nm and 380nm) to ultraviolet rays, X-rays, gamma rays and cosmic rays with wavelengths as short as 8 ✕ 10−12mm. All these electromagnetic waves differ only in frequency (and wavelength) but have the same speed as light in a vacuum.
equal energy spectrum Spectrum in which all wavelengths have about the same amount of energy. See achromatic; white light.
fortification spectrum See scintillating scotoma.
invisible spectrum The portions of the entire electromagnetic spectrum that are made up of radiations other than those of the visible spectrum.
line spectrum Spectrum consisting of a series of discrete monochromatic lines (or narrow bands of monochromatic light) with large intensity differences and separated by intervals without radiations. Example: the spectrum emitted by an electric discharge through a gas or vapour under low pressure.
spectrum locus The representation of the spectral colour stimuli on a chromaticity diagram.
solar spectrum The spectrum formed by sunlight. It is crossed at intervals by Fraunhofer's lines.
visible spectrum The portion of the electromagnetic spectrum that can be perceived by the visual system. It is composed of radiations of wavelengths in the range between 380nm and 780nm in younger eyes. This range decreases with age especially due to lens absorption of short wavelengths becoming closer to 420nm than 380nm. See light.

Table S4 Approximate values of the velocity, frequency and wavelength of electromagnetic radiations in a vacuum (the values represent a point within a range of radiations)
wavelength
radiationvelocity (m/s)frequency (Hz)(m)(nm)
AM radio3 ✕ 108 1 ✕ 106 3 ✕ 1023 ✕ 1011
television3 ✕ 108 1 ✕ 108 33 ✕ 109
radar3 ✕ 108 1 ✕ 109 3 ✕ 10−13 ✕ 108
microwave3 ✕ 108 1 ✕ 1010 3 ✕ 10−23 ✕ 107
thermal infrared3 ✕ 108 1 ✕ 1013 3 ✕ 10−53 ✕ 104
near infrared3 ✕ 108 1 ✕ 1014 3 ✕ 10−63000
light
red3 ✕ 1083.94 ✕ 10147.6 ✕ 10−7760
yellow3 ✕ 1085.45 ✕ 10145.5 ✕ 10−7550
violet3 ✕ 1087.50 ✕ 10144.0 ✕ 10−7400
ultraviolet3 ✕ 108 1 ✕ 1016 3 ✕ 10−830
X-rays3 ✕ 108 1 ✕ 1018 3 ✕ 10−100.3
gamma rays3 ✕ 108 1 ✕ 1021 3 ✕ 10−130.0003

spec·trum

, pl. spectrums, pl. spectra (spek'trŭm, -trŭmz, -tră)
1. Range of colors presented when white light is resolved into its constituent colors by being passed through a prism or through a diffraction grating: red, orange, yellow, green, blue, indigo, and violet.
2. Range of pathogenic microorganisms against which an antibiotic or other antibacterial agent is active.
[L. an image, fr. specio, to look at]

Patient discussion about spectrum

Q. What is the difference between autism, and autism spectrum? Doctor states my child is autistic, school says he has autism spectrum disorder. What is the difference? Can medication help with any of this?

A. i agree with Lilian- it's just a way for schools to keep their behinds clean...

Q. What is a "spectrum disorder" mean? I just heard/read about spectrum disorder, What is a "spectrum disorder" mean?

A. Autism is a spectrum disorder where symptoms and characteristics can present themselves in a wide variety of combinations, from mild to severe and in any combination. A high functioning individual with autism might simply seem eccentric, a loner. More severely affected individuals may hardly communicate and prefer to function primarily in "their own world". Most individuals fall in the middle of the spectrum.

Q. What shall I do with my 3 years old son with autism spectrum disorder. What shall I do with my 3 years old son with autism spectrum disorder to increase on his Sensory Integration. I feel therapy is too costly to afford….Is there any alternative.

A. there are some computer software that can do that too, and it doesn't cost all that much.they combine hearing- seeing and feeling.
i saw a computer USB contraption that also work int hat method and i think it costs 150-200 $ ...not sure....

More discussions about spectrum
References in periodicals archive ?
Huawei has accumulated years of research and development on Massive MIMO and self-developed antennas in the 2.6GHz frequency band. In the 5G era, Huawei wakens the accumulated advantages with great power.
DOCOMO and Rohde & Schwarz confirmed that they can measure and analyze the shielding effect of the human body, applying signals up to 150 GHz in all common 5G frequency bands currently in use or under consideration.
6 shows the frequency bands for TETRA, UHF, and Super Wi-Fi, which were redefined so as not to overlap.
The designed antenna should achieve the requirements of UWB frequency band and good directional radiation, simultaneously.
In 2013, the proliferation of signal interference prompted the NTC to issue Memorandum Order 01-02-2013, prohibiting the sale, purchase, importation, possession or use of signal boosters operating on the 800 megahertz, 900 MHz, 1800 MHz, and 2100 MHz frequency bands without the approval of the regulatory agency.
The results show that the optimum RT for identifying an image filtered in different spatial frequency bands was approximately 2000 ms of exposure.
Figure 8 presents RMS tendencies along y-direction in different frequency bands versus cavitation number when the model pump operates at the nominal flow rate.
Figure 7 shows the maximum SPL reductions of the frequency bands of interest in the central gap by using asymmetric gradient assembly designs.
Two-sample t-tests were used to examine the significance of group differences in age, education, and neuropsychological scores, as well as the group differences of RSNs functional connectivity matrix in different frequency bands (0.01-0.027 Hz, 0.027-0.08 Hz, and 0.01-0.08 Hz).
The National Telecom Regulatory Authority (NTRA) has redistributed the 4G frequency bands among mobile operators after the three companies refused to bid for the licence in September, calling for negotiations with the Ministry of Communications and Information Technology and NTRA officials.
Zinwave's UNItivity wideband distributed antenna system (DAS) is the only system that is ready for mobile operator upgrades to AWS-3 and 600 MHz frequency bands.
This offer will enable it to choose unit 1 (Siliana, Kasserine and Tozeur) and unit 4 (Beja and Zaghouan) and work on frequency bands "A1".

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