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quality of transparency of modern optical transmission. The medium is typically a fiber of silica glass that confines the incident light beam to the inside. Attenuation is an important factor limiting the transmission of a digital signal across large distances. Thus, much research has gone into both limiting the attenuation and maximizing the amplification of the optical signal. Empirical research has shown that attenuation in optical fiber is caused primarily by both scattering and absorption.
1072:
1207:
1223:"diffuse reflection", and it is typically characterized by wide variety of reflection angles. Most objects that can be seen with the naked eye are visible due to diffuse reflection. Another term commonly used for this type of reflection is "light scattering". Light scattering from the surfaces of objects is our primary mechanism of physical observation. Light scattering from many common surfaces can be modelled by reflectance.
151:
1235:"domains" exhibiting various degrees of short-range order become the building-blocks of both metals and alloys, as well as glasses and ceramics. Distributed both between and within these domains are microstructural defects that will provide the most ideal locations for the occurrence of light scattering. This same phenomenon is seen as one of the limiting factors in the transparency of IR missile domes.
753:-a pigments in the phytoplankton absorb light, and the plants themselves scatter light, making coastal waters less clear than mid-ocean waters. Chlorophyll-a absorbs light most strongly in the shortest wavelengths (blue and violet) of the visible spectrum. In coastal waters where high concentrations of phytoplankton occur, the green wavelength reaches the deepest in the water column and the
1109:
chances of interacting with matter. This is mainly due to the photoelectric effect which states that "the probability of photoelectric absorption is approximately proportional to (Z/E), where Z is the atomic number of the tissue atom and E is the photon energy. In context of this, an increase in photon energy (E) will result in a rapid decrease in the interaction with matter.
1231:
crystalline order. It has recently been shown that, when the size of the scattering center (or grain boundary) is reduced below the size of the wavelength of the light being scattered, the scattering no longer occurs to any significant extent. This phenomenon has given rise to the production of transparent ceramic materials.
1257:
The selective absorption of infrared (IR) light by a particular material occurs because the selected frequency of the light wave matches the frequency (or an integral multiple of the frequency) at which the particles of that material vibrate. Since different atoms and molecules have different natural
1215:
1123:
Attenuation in fiber optics, also known as transmission loss, is the reduction in intensity of the light beam (or signal) with respect to distance travelled through a transmission medium. Attenuation coefficients in fiber optics usually use units of dB/km through the medium due to the relatively high
1252:
At the atomic or molecular level, it depends on the frequencies of atomic or molecular vibrations or chemical bonds, how close-packed its atoms or molecules are, and whether or not the atoms or molecules exhibit long-range order. These factors will determine the capacity of the material transmitting
216:
of the ultrasound beam as a function of distance through the imaging medium. Accounting for attenuation effects in ultrasound is important because a reduced signal amplitude can affect the quality of the image produced. By knowing the attenuation that an ultrasound beam experiences traveling through
1108:
The beam of X-ray is attenuated when photons are absorbed when the x-ray beam passes through the tissue. Interaction with matter varies between high energy photons and low energy photons. Photons travelling at higher energy are more capable of travelling through a tissue specimen as they have less
725:
of light that range from 360 nm (violet) to 750 nm (red). When the Sun's radiation reaches the sea surface, the shortwave radiation is attenuated by the water, and the intensity of light decreases exponentially with water depth. The intensity of light at depth can be calculated using the
1226:
Light scattering depends on the wavelength of the light being scattered. Thus, limits to spatial scales of visibility arise, depending on the frequency of the incident lightwave and the physical dimension (or spatial scale) of the scattering center, which is typically in the form of some specific
1234:
Likewise, the scattering of light in optical quality glass fiber is caused by molecular-level irregularities (compositional fluctuations) in the glass structure. Indeed, one emerging school of thought is that a glass is simply the limiting case of a polycrystalline solid. Within this framework,
1222:
The propagation of light through the core of an optical fiber is based on total internal reflection of the lightwave. Rough and irregular surfaces, even at the molecular level of the glass, can cause light rays to be reflected in many random directions. This type of reflection is referred to as
1230:
Thus, attenuation results from the incoherent scattering of light at internal surfaces and interfaces. In (poly)crystalline materials such as metals and ceramics, in addition to pores, most of the internal surfaces or interfaces are in the form of grain boundaries that separate tiny regions of
1190:
1243:
In addition to light scattering, attenuation or signal loss can also occur due to selective absorption of specific wavelengths, in a manner similar to that responsible for the appearance of color. Primary material considerations include both electrons and molecules as follows:
432:). Attenuation coefficients vary widely for different media. In biomedical ultrasound imaging however, biological materials and water are the most commonly used media. The attenuation coefficients of common biological materials at a frequency of 1 MHz are listed below:
1270:, attenuation is the rate at which the signal light decreases in intensity. For this reason, glass fiber (which has a low attenuation) is used for long-distance fiber optic cables; plastic fiber has a higher attenuation and, hence, shorter range. There also exist
1248:
At the electronic level, it depends on whether the electron orbitals are spaced (or "quantized") such that they can absorb a quantum of light (or photon) of a specific wavelength or frequency in the ultraviolet (UV) or visible ranges. This is what gives rise to
997:
733:
In clear mid-ocean waters, visible light is absorbed most strongly at the longest wavelengths. Thus, red, orange, and yellow wavelengths are totally absorbed at shallower depths, while blue and violet wavelengths reach deeper in the
419:
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Due to the damaging effects of high-energy photons, it is necessary to know how much energy is deposited in tissue during diagnostic treatments involving such radiation. In addition, gamma radiation is used in
1133:
895:
1227:
microstructural feature. For example, since visible light has a wavelength scale on the order of one micrometer, scattering centers will have dimensions on a similar spatial scale.
497:
1641:
Müller, Tobias M.; Gurevich, Boris; Lebedev, Maxim (September 2010). "Seismic wave attenuation and dispersion resulting from wave-induced flow in porous rocks — A review".
1325:. Attenuation limits the range of radio signals and is affected by the materials a signal must travel through (e.g., air, wood, concrete, rain). See the article on
316:
1054:
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geometric spreading. Therefore, calculation of the total change in intensity involves both the inverse-square law and an estimation of attenuation over the path.
294:
are used to quantify different media according to how strongly the transmitted ultrasound amplitude decreases as a function of frequency. The attenuation
1728:
328:
1185:{\displaystyle {\text{Attenuation (dB)}}=10\times \log _{10}\left({\frac {\text{Input intensity (W)}}{\text{Output intensity (W)}}}\right)}
838:, intrinsic attenuation of seismic waves is primarily caused by the wave-induced flow of the pore fluid relative to the solid frame.
1479:
S. P. Näsholm and S. Holm, "On a
Fractional Zener Elastic Wave Equation," Fract. Calc. Appl. Anal. Vol. 16, No 1 (2013), pp. 26–50,
1258:
frequencies of vibration, they will selectively absorb different frequencies (or portions of the spectrum) of infrared (IR) light.
1498:
Stokes, G.G. "On the theories of the internal friction in fluids in motion, and of the equilibrium and motion of elastic solids",
1850:
1540:
851:
17:
277:
In homogeneous media, the main physical properties contributing to sound attenuation are viscosity and thermal conductivity.
1705:
1511:
G. Kirchhoff, "Ueber den
Einfluss der Wärmeleitung in einem Gase auf die Schallbewegung", Ann. Phys. , 210: 177-193 (1868).
429:
738:. Because the blue and violet wavelengths are absorbed least compared to the other wavelengths, open-ocean waters appear
703:
255:
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is the input power into a 100 m long cable terminated with the nominal value of its characteristic impedance, and
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a medium, one can adjust the input signal amplitude to compensate for any loss of energy at the desired imaging depth.
1825:
1620:
1285:, as raindrops absorb a part of the emitted beam that is more or less significant, depending on the wavelength used.
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Attenuation is linearly dependent on the medium length and attenuation coefficient, as well as – approximately – the
428:
of the incident ultrasound beam for biological tissue (while for simpler media, such as air, the relationship is
123:
992:{\displaystyle {\text{Attenuation (dB/100m)}}=10\times \log _{10}\left({\frac {P_{1}\ (W)}{P_{2}\ (W)}}\right),}
1798:
Archibald, P.S. and
Bennett, H.E., "Scattering from infrared missile domes", Opt. Engr., Vol. 17, p.647 (1978)
445:
1739:
31:
1523:
S. Benjelloun and J. M. Ghidaglia, "On the dispersion relation for compressible Navier-Stokes
Equations,"
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1583:
1322:
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Bohren, C. F. and
Huffman, D.R. "Absorption and Scattering of Light by Small Particles", Wiley, (1983),
237:
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where it is important to know how much energy will be deposited in healthy and in tumorous tissue.
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NIST's XAAMDI: X-Ray
Attenuation and Absorption for Materials of Dosimetric Interest Database
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intensity plays an important role in the assessment of possible strong groundshaking. A
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1757:"X-Ray Physics: X-Ray Interaction with Matter, X-Ray Contrast, and Dose – XRayPhysics"
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Dukhin, A.S. and Goetz, P.J. "Ultrasound for characterizing colloids", Elsevier, 2002
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attenuation defines the local or global influence of light sources and force fields.
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ISO 20998-1:2006 "Measurement and characterization of particles by acoustic methods"
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Attenuation in a coaxial cable is a function of the materials and the construction.
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geometric dispersion caused by distribution of the seismic energy to greater volumes
154:
Frequency-dependent attenuation of electromagnetic radiation in standard atmosphere.
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Diagnostic
Ultrasound, Stewart C. Bushong and Benjamin R. Archer, Mosby Inc., 1991.
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Attenuation and
Dispersion of Elastic Waves in Porous Rocks: Mechanisms and models
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Culjat, Martin O.; Goldenberg, David; Tewari, Priyamvada; Singh, Rahul S. (2010).
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dispersion as heat, also called intrinsic attenuation or anelastic attenuation.
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longer wavelengths in the infrared (IR), far IR, radio and microwave ranges.
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Attenuation in fiber optics can be quantified using the following equation:
414:{\displaystyle {\text{Attenuation}}=\alpha \left\cdot \ell \cdot {\text{f}}}
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1584:"Ultrasound attenuation dependence on air temperature in closed chambers"
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per unit length of medium (dB/cm, dB/km, etc.) and is represented by the
96:
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One area of research in which attenuation plays a prominent role, is in
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Essentials of
Ultrasound Physics, James A. Zagzebski, Mosby Inc., 1996.
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media is associated only with absorption and can be characterized with
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Mandelstam, L.I. (1926). "Light
Scattering by Inhomogeneous Media".
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This article is about attenuation in physics. For other uses, see
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Attenuation is an important consideration in the modern world of
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862:. Attenuation does not include the decrease in intensity due to
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of the path length through the medium. In optics and in chemical
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of the seismic energy with the distance. There are two types of
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for more information on signal loss in wireless communication.
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that decrease the signal in a fiber optic cable intentionally.
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1307:, attenuation describes the density or darkness of the image.
170:. In engineering, attenuation is usually measured in units of
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into account can be written on a fractional derivative form.
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1541:"A Review of Tissue Substitutes for Ultrasound Imaging"
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physics. Attenuation in ultrasound is the reduction in
674:
There are two general ways of acoustic energy losses:
178:
of the medium in question. Attenuation also occurs in
99:
from flowing into the ears. This phenomenon is called
1640:
1281:. This same effect is an important consideration in
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898:
448:
331:
304:
1729:"Technical Information – Coaxial Transmission Lines"
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The primary causes of attenuation in matter are the
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are commonly manufactured components in this field.
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Transactions of the Cambridge Philosophical Society
1581:
1184:
1056:is the output power at the far end of this cable.
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190:, they grow smaller as they are attenuated by the
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318:) can be used to determine total attenuation in
877:, and, for photon energies of above 1.022 MeV,
694:media requires taking into account scattering.
27:Gradual loss of flux intensity through a medium
1821:NIST's FAST: Attenuation and Scattering Tables
721:emitted from the Sun have wavelengths in the
697:
240:. There is an ISO standard on this technique.
889:The attenuation of RF cables is defined by:
745:Near the shore, coastal water contains more
1816:NIST's XCOM: Photon Cross Sections Database
1686:Gurevich, Boris; Carcione, José M. (2022).
322:in the medium using the following formula:
1277:Attenuation of light is also important in
779:affects a location depends on the running
280:
1670:
1517:
1692:. Society of Exploration Geophysicists.
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1205:
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1238:
846:Attenuation decreases the intensity of
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749:than the very clear mid-ocean waters.
492:{\displaystyle \alpha {\text{ }}\left}
1582:JakeviÄŤius, L.; DemÄŤenko, A. (2008).
1532:
1545:Ultrasound in Medicine & Biology
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783:. The attenuation in the signal of
704:Electromagnetic absorption by water
24:
1557:10.1016/j.ultrasmedbio.2010.02.012
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25:
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1804:
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682:. Ultrasound propagation through
158:In many cases, attenuation is an
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1502:, vol.8, 22, pp. 287-342 (1845)
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89:at variable attenuation rates.
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32:Attenuation (disambiguation)
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1323:wireless telecommunications
186:move farther away from the
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698:Light attenuation in water
690:only. Propagation through
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270:Wave equations which take
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118:, attenuation affects the
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1380:Environmental remediation
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848:electromagnetic radiation
775:The energy with which an
49:) is the gradual loss of
1591:Ultragarsas (Ultrasound)
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292:Attenuation coefficients
236:, yields information on
1782:Zh. Russ. Fiz-Khim. Ova
1698:10.1190/1.9781560803911
1370:Cross section (physics)
311:{\displaystyle \alpha }
287:Attenuation coefficient
281:Attenuation coefficient
250:measurement. There are
176:attenuation coefficient
166:, this is known as the
1525:Link to Archiv e-print
1389:Extinction (astronomy)
1355:Atmospheric refraction
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688:absorption coefficient
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244:Ultrasound attenuation
222:Ultrasound attenuation
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136:Electrical attenuators
112:electrical engineering
18:Ultrasound attenuation
1365:Attenuator (genetics)
1279:physical oceanography
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1119:Transparent materials
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1049:{\displaystyle P_{2}}
1024:
1022:{\displaystyle P_{1}}
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901:Attenuation (dB/100m)
708:Further information:
654:Soft tissue (average)
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260:extensional viscosity
153:
57:. For instance, dark
1649:(5): 75A147–75A164.
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1174:Output intensity (W)
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272:acoustic attenuation
248:extensional rheology
204:Acoustic attenuation
160:exponential function
120:propagation of waves
101:acoustic attenuation
53:intensity through a
1655:2010Geop...75A.147M
1528:Link to Hal e-print
1384:natural attenuation
1350:Astronomical seeing
1345:Astronomical filter
1272:optical attenuators
1210:Specular reflection
1171:Input intensity (W)
801:seismic attenuation
719:Shortwave radiation
436:
252:acoustic rheometers
140:optical attenuators
128:electrical circuits
103:and is measured in
45:(in some contexts,
1841:Physical phenomena
1672:20.500.11937/35921
1360:Attenuation length
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1218:Diffuse reflection
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1082:. You can help by
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864:inverse-square law
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116:telecommunications
93:Hearing protectors
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840:
824:
823:
820:
772:
769:
755:color of water
710:Color of water
702:Main article:
699:
696:
670:
669:
666:
660:
659:
656:
650:
649:
646:
640:
639:
636:
630:
629:
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620:
619:
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610:
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579:
576:
570:
569:
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550:
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546:
540:
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531:
528:
521:
520:
517:
511:
510:
507:
500:
499:
487:
475:
460:
451:
441:
422:
421:
410:
402:
394:
391:
383:
380:
377:
373:
361:
346:
342:
339:
307:
285:Main article:
282:
279:
268:
267:
258:for measuring
241:
228:systems, like
202:Main article:
199:
196:
147:
144:
134:, and in air.
132:optical fibers
26:
9:
6:
4:
3:
2:
1863:
1852:
1849:
1847:
1844:
1842:
1839:
1838:
1836:
1827:
1824:
1822:
1819:
1817:
1814:
1812:
1809:
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1795:
1787:
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1762:
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1741:
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1703:
1699:
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1682:
1673:
1668:
1664:
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1656:
1652:
1648:
1644:
1637:
1628:
1622:
1621:0-471-29340-7
1618:
1612:
1604:
1600:
1596:
1592:
1585:
1578:
1570:
1566:
1562:
1558:
1554:
1550:
1546:
1542:
1535:
1529:
1526:
1520:
1514:
1513:Link to paper
1508:
1501:
1495:
1489:
1486:
1482:
1476:
1467:
1458:
1449:
1445:
1435:
1432:
1430:
1427:
1425:
1424:Sunset#Colors
1422:
1420:
1417:
1415:
1412:
1410:
1409:Radar horizon
1407:
1405:
1402:
1400:
1397:
1395:
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1390:
1387:
1385:
1381:
1378:
1376:
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1368:
1366:
1363:
1361:
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1328:
1324:
1318:
1308:
1306:
1301:
1299:
1294:
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1286:
1284:
1283:weather radar
1280:
1275:
1273:
1269:
1259:
1251:
1247:
1246:
1245:
1236:
1232:
1228:
1224:
1216:
1208:
1203:
1178:
1165:
1161:
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1145:
1142:
1130:
1129:
1128:
1125:
1120:
1110:
1105:
1094:
1085:
1081:
1078:This section
1076:
1073:
1069:
1068:
1060:
1057:
1041:
1037:
1014:
1010:
986:
982:
973:
962:
958:
949:
938:
934:
927:
923:
918:
914:
910:
907:
904:
892:
891:
890:
882:
880:
876:
872:
867:
865:
861:
857:
853:
849:
839:
837:
833:
829:
821:
818:
817:
816:
814:
810:
806:
802:
798:
794:
790:
786:
785:ground motion
782:
778:
768:
766:
764:
760:
756:
752:
748:
747:phytoplankton
743:
741:
737:
731:
729:
724:
720:
715:
711:
705:
695:
693:
692:heterogeneous
689:
685:
681:
677:
667:
665:
662:
661:
657:
655:
652:
651:
647:
645:
642:
641:
637:
635:
632:
631:
627:
625:
622:
621:
617:
615:
612:
611:
607:
605:
602:
601:
597:
595:
592:
591:
587:
585:
582:
581:
577:
575:
572:
571:
567:
565:
562:
561:
557:
555:
552:
551:
547:
545:
542:
541:
537:
534:
533:
529:
526:
523:
522:
518:
516:
513:
512:
508:
505:
502:
501:
485:
473:
458:
449:
442:
439:
438:
433:
431:
427:
392:
378:
375:
371:
359:
344:
340:
337:
325:
324:
323:
321:
305:
297:
293:
288:
278:
275:
273:
265:
261:
257:
253:
249:
245:
242:
239:
235:
231:
227:
226:heterogeneous
223:
220:
219:
218:
215:
211:
205:
195:
193:
189:
185:
184:seismic waves
181:
177:
173:
169:
165:
161:
152:
143:
141:
137:
133:
129:
125:
121:
117:
113:
108:
106:
102:
98:
97:acoustic flux
94:
90:
88:
84:
80:
76:
72:
68:
64:
60:
56:
52:
48:
44:
40:
33:
19:
1794:
1785:
1781:
1775:
1764:. Retrieved
1760:
1751:
1740:the original
1736:rfsworld.com
1735:
1723:
1711:. Retrieved
1688:
1681:
1646:
1642:
1636:
1627:
1611:
1597:(1): 18–22.
1594:
1590:
1577:
1569:the original
1548:
1544:
1534:
1519:
1507:
1499:
1494:
1475:
1466:
1457:
1448:
1383:
1320:
1302:
1295:
1287:
1276:
1265:
1262:Applications
1256:
1242:
1233:
1229:
1225:
1221:
1126:
1122:
1107:
1088:
1084:adding to it
1079:
1058:
1001:
888:
868:
845:
825:
800:
789:seismic wave
774:
767:
744:
742:to the eye.
736:water column
732:
717:
673:
423:
290:
276:
269:
254:that employ
243:
221:
207:
164:spectroscopy
157:
109:
95:help reduce
91:
46:
42:
36:
1713:26 February
1394:ITU-R P.525
1104:Radiography
1063:Radiography
751:Chlorophyll
714:Ocean color
684:homogeneous
527:, cortical
334:Attenuation
296:coefficient
256:Stokes' law
182:; when the
180:earthquakes
69:attenuates
43:attenuation
1835:Categories
1766:2018-09-21
1643:Geophysics
1441:References
1305:CT imaging
1091:March 2018
856:scattering
852:absorption
836:sandstones
813:dissipated
809:dispersion
805:phenomenon
777:earthquake
759:blue-green
680:scattering
676:absorption
210:ultrasound
198:Ultrasound
188:hypocenter
146:Background
61:attenuate
47:extinction
1846:Acoustics
1603:1392-2114
1429:Twinkling
1419:Rain fade
1404:Path loss
1327:path loss
1317:Path loss
1162:
1149:×
924:
911:×
740:deep blue
474:⋅
450:α
430:quadratic
426:frequency
393:⋅
379:ℓ
376:⋅
360:⋅
341:α
306:α
230:emulsions
214:amplitude
1565:20510184
1333:See also
834:such as
815:energy:
803:). This
781:distance
757:appears
440:Material
234:colloids
172:decibels
105:decibels
63:sunlight
1651:Bibcode
860:photons
850:due to
771:Seismic
668:0.0022
564:Cardiac
124:signals
107:(dBs).
59:glasses
39:physics
1788:: 381.
1704:
1619:
1601:
1563:
1249:color.
1113:Optics
1002:where
968:
944:
828:porous
793:energy
791:loses
644:Tendon
634:Muscle
624:Marrow
594:Enamel
584:Dentin
554:Breast
454:
192:ground
73:, and
71:X-rays
55:medium
1743:(PDF)
1732:(PDF)
1587:(PDF)
1311:Radio
797:earth
763:green
664:Water
658:0.54
638:1.09
614:Liver
608:0.48
578:1.57
568:0.52
558:0.75
544:Brain
538:9.94
515:Blood
509:1.64
130:, in
87:sound
83:light
75:water
1715:2023
1702:ISBN
1617:ISBN
1599:ISSN
1561:PMID
1382:for
712:and
678:and
648:4.7
628:0.5
618:0.5
598:120
548:0.6
530:6.9
525:Bone
519:0.2
262:and
138:and
122:and
114:and
85:and
77:and
67:lead
51:flux
1694:doi
1667:hdl
1659:doi
1553:doi
1481:doi
1303:In
1296:In
1266:In
1153:log
1086:.
915:log
858:of
854:or
826:In
761:or
604:Fat
588:80
504:Air
469:MHz
405:MHz
355:MHz
232:or
126:in
110:In
79:air
37:In
1837::
1786:58
1784:.
1759:.
1734:.
1700:.
1665:.
1657:.
1647:75
1645:.
1595:63
1593:.
1589:.
1559:.
1549:36
1547:.
1543:.
1157:10
1146:10
919:10
908:10
881:.
873:,
765:.
730:.
479:cm
464:dB
386:cm
365:cm
350:dB
320:dB
194:.
65:,
41:,
1769:.
1717:.
1696::
1675:.
1669::
1661::
1653::
1605:.
1555::
1483::
1179:)
1166:(
1143:=
1093:)
1089:(
1042:2
1038:P
1015:1
1011:P
987:,
983:)
977:)
974:W
971:(
963:2
959:P
953:)
950:W
947:(
939:1
935:P
928:(
905:=
799:(
486:]
459:[
409:]
401:[
397:f
390:]
382:[
372:]
345:[
338:=
298:(
266:.
34:.
20:)
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