Sheet Input

Attenuation - China Sheet Metal Fabrication - Sheet Metal cabinet Manufacturer

Background
In many cases, attenuation is an exponential function of the path length through the medium. In chemical spectroscopy, this is known as the Beer-Lambert law.
In engineering, attenuation is usually measured in units of decibels per unit length of medium (dB/cm, dB/km, etc) and is represented by the attenuation coefficient of the medium in question.
Frequency dependent attenuation of electromagnetic radiation in standard atmosphere.
Attenuation also occurs in earthquakes; when the seismic waves move farther away from the epicenter, they grow smaller as they are attenuated by the ground. Ultrasound
One area of research in which attenuation figures strongly is in ultrasound physics. Attenuation in ultrasound is the reduction in amplitude 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 a medium, one can adjust the input signal amplitude to compensate for any loss of energy at the desired imaging depth.
Ultrasound attenuation measurement in heterogeneous systems, like emulsions or colloids yields information on particle size distribution. There is an ISO standard on this technique.
Ultrasound attenuation can be used for extensional rheology measurement. There are acoustic rheometers that employ Stokes' law for measuring extensional viscosity and volume viscosity. Attenuation coefficient
Attenuation coefficients are used to quantify different media according to how strongly the transmitted ultrasound amplitude decreases as a function of frequency. The attenuation coefficient () can be used to determine total attenuation in dB in the medium using the following formula:
As this equation shows, besides the medium length and attenuation coefficient, attenuation is also linearly dependent on the frequency of the incident ultrasound beam. 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:
Material
(dB / (MHz * cm))
Lung
41
Bone
20
Kidney
1.0
Liver
0.94
Brain
0.85
Fat
0.63
Blood
0.18
Water
0.23222
There are two general ways of acoustic energy losses: absorption and scattering, for instance light scattering. Ultrasound propagation through homogeneous media is associated only with absorption and can be characterized with absorption coefficient only. Propagation through heterogeneous media requires taking into account scattering. Earthquake
The energy with which an earthquake affects a location depends on the running distance. The attenuation in the signal of ground motion intensity plays an important role in the assessment of possible strong ground shaking. A seismic wave loses energy as it propagates through the earth (attenuation). This phenomenon is tied in to the dispersion of the seismic energy with the distance. There are two types of dissipated energy:
geometric dispersion caused by distribution of the seismic energy to greater volumes
dispersion as heat Electromagnetic
Attenuation decreases the intensity of electromagnetic radiation due to absorption or scattering of photons. Attenuation does not include the decrease in intensity due to inverse-square law geometric spreading. Therefore, calculation of the total change in intensity involves both the inverse-square law and an estimation of attenuation over the path.
The primary causes of attenuation in matter are the photoelectric effect, compton scattering and, for photon energies of above 1.022MeV, pair production. Radiography
See Attenuation coefficient article. Optics
Main article: Transparent materials
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 quality of transparency of modern optical transmission media. 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. Attenuation in fiber optics can be quantified using the following equation: Light scattering
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. We refer to this type of reflection as "diffuse reflection", and it is typically characterized by wide variety of reflection angles. Most of the objects that you see 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. Specular Reflection
Diffuse Reflection
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 microstructural feature. E.G. Since visible light has a wavelength scale on the order of one micron (one millionth of a meter), scattering centers will have dimensions on a similar spatial scale.
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 which separate tiny regions of 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.
Similarly, 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, "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 which 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.
See Physics of glass UV-Vis-IR absorption
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:
1) 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 color.
2) 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 longer wavelengths in the infrared (IR), far IR, radio and microwave ranges.
The design of any optically transparent device requires the selection of materials based upon knowledge of its properties and limitations. The lattice absorption characteristics observed at the lower frequency regions (mid IR to far-infrared wavelength range) define the long-wavelength transparency limit of the material. They are the result of the interactive coupling between the motions of thermally induced vibrations of the constituent atoms and molecules of the solid lattice and the incident light wave radiation. Hence, all materials are bounded by limiting regions of absorption caused by atomic and molecular vibrations (bond-stretching)in the far-infrared (>10 m).
Thus, multi-phonon absorption occurs when two or more phonons simultaneously interact to produce electric dipole moments with which the incident radiation may couple. These dipoles can absorb energy from the incident radiation, reaching a maximum coupling with the radiation when the frequency is equal to the fundamental vibrational mode of the molecular dipole (e.g. Si-O bond) in the far-infrared, or one of its harmonics.
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 frequencies of vibration, they will selectively absorb different frequencies (or portions of the spectrum) of infrared (IR) light.
Reflection and transmission of light waves occur because the frequencies of the light waves do not match the natural resonant frequencies of vibration of the objects. When IR light of these frequencies strike an object, the energy is either reflected or transmitted. Applications
In optical fibers, 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 optical attenuators which decrease the signal in a fiber optic cable intentionally.
Attenuation of light is also important in physical oceanography. Here, attenuation is the decrease in light intensity with depth due to absorption by water molecules and scattering by suspended particulates. This same effect is an important consideration in weather radar as rain drops absorb a part of the emitted beam that is more or less significant depending on the wavelength used.
The attenuation of photons, particularly of those in the x-ray spectrum, is important in the field of medical physics. 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. Additionally gamma radiation is used in cancer treatments where it is important to know how much energy will be deposited in healthy and in tumorous tissue. Radio
Main article: Path loss
Attenuation is an important consideration in the modern world of wireless telecommunication. 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 path loss for more information on signal loss in wireless communication. Power vs Amplitude
Attenuation of a signal's power by n decibels is equivalent to attenuating its amplitude by 2*n decibels. See also
Attenuator (electronics)
Attenuator (genetics)
Cross section (physics)
Electrical impedance
Environmental remediation for natural attenuation
Mean free path
Path loss
Rain Fade
Radiation length
Radiography
Wave propagation External links
NIST's XAAMDI: X-Ray Attenuation and Absorption for Materials of Dosimetric Interest Database
NIST's XCOM: Photon Cross Sections Database
NIST's FAST: Attenuation and Scattering Tables
Underwater Radio Communication References
^ Essentials of Ultrasound Physics, James A. Zagzebski, Mosby Inc., 1996.
^ a b Diagnostic Ultrasound, Stewart C. Bushong and Benjamin R. Archer, Mosby Inc., 1991.
^ ISO 20998-1:2006 "Measurement and characterization of particles by acoustic methods"
^ Bohren,C. F. and Huffman, D.R. "Absorption and Scattering of Light by Small Particles", Wiley, (1983), isbn= 0-471-29340-7
^ Dukhin, A.S. and Goetz, P.J. "Ultrasound for characterizing colloids", Elsevier, 2002
^ Telecommunications: A Boost for Fibre Optics, Z. Valy Vardeny, Nature 416, 489491, 2002.
^ "Fibre Optics". Bell College. http://web.archive.org/web/20060224231950/http://floti.bell.ac.uk/MATHSPHYSICS/5attenua.htm. 
^ Kerker, M. (1909). The Scattering of Light (Academic, New York). 
^ Mandelstam, L.I. (1926). "Light Scattering by Inhomogeneous Media". Zh. Russ. Fiz-Khim. Ova. 58: 381. 
^ Archibald, P.S. and Bennett, H.E., "Scattering from infrared missile domes", Opt. Engr., Vol. 17, p.647 (1978) Categories: Communication engineering | Acoustics
About the Author

The e-commerce company in China offers quality products such as China Sheet Metal Fabrication , Sheet Metal cabinet Manufacturer, and more. For more , please visit machining parts Manufacturer today!

Lexmark Sheet Input Drawer $182.99 250 250 Sheet 30G0820 60 g/m² to 135 g/m² Lexmark: T65X X651 X652 X654 X656 Card Stock Label Lexmark Lexmark International, Inc Plain Paper Sheet Sheet Drawer Sheet Input Drawer Transparency www.lexmark.com

HP LASERJET 1500 SHEET INPUT TRAY CE398A $561.38 HP LASERJET 1500 SHEET INPUT TRAY CE398A

Konica Minolta 500 Sheet Lower Input Feeder $459.99 4067614 500 500 Sheet 500 Sheet Lower Input Feeder Konica Minolta Sheet Sheet Feeder www.konicaminolta.us

30G0804 T65x 2000 Sheet High Capacity Input Drawer - 2000 Sheet $479.99 30G0804 T65x 2000 Sheet High Capacity Input Drawer - 2000 Sheet

Lexmark T65x 550 Sheet Input Tray $103.99 30G0803 550 550 Sheet Lexmark Lexmark International, Inc Paper Tray Sheet T65x 550 Sheet Input Tray www.lexmark.com

Lexmark T65x 2000 Sheet High Capacity Input Drawer 30G0804 $518.56 Lexmark T65x 2000 Sheet High Capacity Input Drawer 30G0804

Lexmark T65x 2000 Sheet High Capacity Input Drawer $454.99 2000 2000 Sheet 30G0804 Lexmark Lexmark International, Inc Sheet Sheet Drawer T65x 2000 Sheet High Capacity Input Drawer www.lexmark.com

HP Input Tray for HP Laserjet 3390 and 3392, 250 Sheet. Each $181.08 Manufacturer: HP. Each. Customers also search for: Discount Input Tray for HP Laserjet 3390 and 3392, 250 Sheet, Buy Input Tray for HP Laserjet 3390 and 3392, 250 Sheet, Wholesale Input Tray for HP Laserjet 3390 and 3392, 250 Sheet, 882780149526, Laser Su

550 Sheet Input Drawer Option $237.99 This unit supports A4 A5 JIS B5 Letter Legal Executive Folio and Statementsizes. Paper (16 to 47 lb. 60 to 176 gsm) transparencies card stock and labels may be used

Ce998A - Hp Input Tray Feeder - 500 Sheet $264.15 Support the productivity of growing work groups with simple, robust paper input accessories that enables media versatility, from A4 to legal, and allows longer printing without reloading paper. [3102435] UPC: 886111320066 UNSPC: 44101705 23.5L x 19.5W x 10H 19 LB

30G0820 - Lexmark Sheet Input Drawer - 250 Sheet $218.03 [U43187] UPC: 734646090780 UNSPC: 44101705 22.4L x 19.3W x 6.2H 9.6 LB 1.55 Cubes

HP 500 Sheet Input Tray For P2055 Series Printer $136.99 500 500 Sheet 500 Sheet Input Tray For P2055 Series Printer Print on a range of paper types in sizes from 4.1 x 5.8 in (105 x 148 mm) to 8.5 x 14 in (216 x 356 mm) while increasing total input capacity to up to 800 sheets. Automatically print on two different types of paper such as plain paper and glossy brochure paper without manually loading paper trays for each print job. CE464A HP HP LaserJet P2055 Series Printer Hewlett-Packard Paper Tray Sheet www.hp.com

XEROX PHASER 4600 LASER PRINTER#44; 55PPM#44; NETWORK#44; 1X550 SHEET INPUT TRAY#44; 120V $1267.39 XEROX PHASER 4600 LASER PRINTER 55PPM NETWORK 1X550 SHEET INPUT TRAY 120VPHASER 4600 LASER PRINTER 55PPM NETWORK 1X550 SHEET INPUT TRAY 120V Manufacturer : XEROX UPC : 095205764345

HP INTL LASERU MAINT KIT 220V F/LASERJET 8100 S 2000 SHEET INPUT C3915A $314.85 HP INTL LASERU MAINT KIT 220V F/LASERJET 8100 S 2000 SHEET INPUT C3915A

HEWLETT PACKARD HP 250 sheet input tray Q7556A $259.72 Information technology professionals rely on HP quality to ensure maximum productivity. As the power of applications processors memory adapters and storage devices increases highend computer users are seeking ways to optimize their system performance. HP provides leading solutions adding new levels of performance availability flexibility and management.nbsp;HP 250 sheet input tray accessory for the LaserJet 3390 allinone printer.

HEWLETT PACKARD HP 500 Sheet Input Tray for LJ5200 Q7548A $591.06 Support the productivity of growing work groups with this simple robust paper input accessory that enables media versatility from A4 to legal and allows longer printing without reloading paper. Media Capacity 500 Sheet. Custom Media Sizes: 76.2 x 127 mm to 297 x 431.8 mm (3 x 5 to 11.69 x 17 ). Compatibility: HP LaserJet 5200 Printer 5200n Printer 5200tn Printer and 5200dtn Printer.

HP High Volume Input Tray for LJ9000, 2000 sheets. Each $1191.97 Manufacturer: HP. Each. Input Tray For LJ9000 High volume, 2000 sheet capacity. Customers also search for: HP, 725184869990

XEROX PHASER 4600 LASER PRINTER#44; 55PPM#44; NETWORK#44; 1X550 SHEET INPUT TRAY#44; AUTOMATIC TWO $1505.32 XEROX PHASER 4600 LASER PRINTER 55PPM NETWORK 1X550 SHEET INPUT TRAY AUTOMATIC TWOPHASER 4600 LASER PRINTER 55PPM NETWORK 1X550 SHEET INPUT TRAY AUTOMATIC TWOSIDED PRINTING 120V Manufacturer : XEROX UPC : 095205849844

XEROX PHASER 4620 LASER PRINTER#44; 65PPM#44; NETWORK#44; 1X550 SHEET INPUT TRAY#44; AUTOMATIC TWO $2604.88 XEROX PHASER 4620 LASER PRINTER 65PPM NETWORK 1X550 SHEET INPUT TRAY AUTOMATIC TWOPHASER 4620 LASER PRINTER 65PPM NETWORK 1X550 SHEET INPUT TRAY AUTOMATIC TWOSIDED PRINTING 120V Manufacturer : XEROX UPC : 095205764369

XEROX PHASER 4600 LASER PRINTER#44; 55PPM#44; NETWORK#44; 2X550 SHEET INPUT TRAY#44; AUTOMATIC TWO $1913.76 XEROX PHASER 4600 LASER PRINTER 55PPM NETWORK 2X550 SHEET INPUT TRAY AUTOMATIC TWOPHASER 4600 LASER PRINTER 55PPM NETWORK 2X550 SHEET INPUT TRAY AUTOMATIC TWOSIDED PRINTING 120V Manufacturer : XEROX UPC : 095205878004

XEROX PHASER 4620 LASER PRINTER#44; 65PPM#44; NETWORK#44; 2X550 SHEET INPUT TRAY#44; AUTOMATIC TWO $3017.85 XEROX PHASER 4620 LASER PRINTER 65PPM NETWORK 2X550 SHEET INPUT TRAY AUTOMATIC TWOPHASER 4620 LASER PRINTER 65PPM NETWORK 2X550 SHEET INPUT TRAY AUTOMATIC TWOSIDED PRINTING 120V Manufacturer : XEROX UPC : 095205877977

30G0803 - Lexmark T65X 550 Sheet Input Tray - 550 Sheet $104.99 [2268311] UPC: 734646074704 UNSPC: 44101705 23.3L x 19.6W x 6.1H 6.25 LB 1.52 Cubes

Lexmark 2000 Sheets Dual Input Feeder For W840 Printer $1285.99 15R0120 2000 2000 Sheet 2000 Sheets Dual Input Feeder For W840 Printer 2000 sheets in 2 trays Either the Dual Input or the 2 x 500-Sheet Drawer may be installed below the printer. Both units cannot be installed at the same time Lexmark W840 Printer Card Stock Card Stock - 17 lb to 28 lb Lexmark Lexmark International, Inc Paper - 17 lb to 28 lb Plain Paper Plain Paper - 20 lb Sheet Sheet Feeder www.lexmark.com

Ce464A - Hp 500 Sheet Input Tray For P2055 Series Printer - 500 Sheet $136.16 print on a Range of Paper Types in Sizes From 4.1 x 5.8 in (105 x 148 Mm) to 8.5 x 14 in (216 x 356 Mm) While Increasing Total Input Capacity to up to 800 Sheets. Automatically Print on Two Different Types of Paper Such as Plain Paper And Glossy Brochure Paper Without Manually Loading Paper Trays For Each Print Job. [2281393] UPC: 883585946518 UNSPC: 44101705 18.50x9.50x19.50 19.5L x 10.1W x 18.4H 10.9 LB 1 Cubes

HP 500-sheet Input Tray For P2055 Series Printer $281.56 Print on a range of paper types in sizes from 4.1 x 5.8 in (105 x 148 mm) to 8.5 x 14 in (216 x 356 mm) while increasing total input capacity to up to 800 sheets. Automatically print on two different types of paper such as plain paper and glossy brochure paper without manually loading paper trays for each print job. Manufacturer: Hewlett-Packard Manufacturer Part Number: CE464A Manufacturer Website Address: www.hp.com Brand Name: HP Product Name: 500 Sheet Input Tray For P2055 Series Printer Product Type: Paper Tray

Konica Minolta 500 Sheets Lower Input Feeder For MagiColor 7450 Laser Printer $367.99 4067612 500 500 Sheet 500 Sheets Lower Input Feeder For MagiColor 7450 Laser Printer Konica Minolta MagiColor 7450 Laser Printer Konica Minolta Sheet Sheet Feeder www.konicaminolta.us

Oki 70063301 Sheet Drawer $253.99 550 550 Sheet 70063301 70063301 Input Drawer OKI MB780 Multifunction Printer Oki Oki Electric Industry Co., Ltd Plain Paper Sheet Sheet Drawer www.okidata.com

Oki 70063302 Sheet Drawer $508.99 2000 2000 Sheet 70063302 70063302 Input Drawer OKI MB780 Multifunction Printer Oki Oki Electric Industry Co., Ltd Plain Paper Sheet Sheet Drawer www.okidata.com

Oki 70063305 Sheet Drawer $255.99 550 550 Sheet 70063305 70063305 Input Drawer OKI Multifunction Printers: MB790 MB790F MB790M Oki Oki Electric Industry Co., Ltd Plain Paper Sheet Sheet Drawer www.okidata.com

HP 500 Sheets Input Tray For CLJ3000, CLJ3600 and CLJ3800 Printers $260.99 500 500 Sheet 500 Sheets Input Tray For CLJ3000, CLJ3600 and CLJ3800 Printers HP CLJ3000 Printer HP CLJ3600 Printer HP CLJ3800 Printer Enhance productivity with a simple-to-install paper tray that delivers flexible media options from A5 to legal. Print on up to 850 sheets[1] without reloading paper. Media sensors and media guides automatically detect the type and size of media. HP Hewlett-Packard Paper Tray Q5985A Sheet www.hp.com

Lexmark 30G0800 T65X250Sheet Input Drawer Option $294.75 This 250Sheet Drawer for the T650 T652 and T654 Series Printers supports A4 A5 JIS B5 letter legal executive folio and statement sizes. Paper size paper and traypresent and traylow sensing are also supported. Primary Information. Product Typenbsp;:nbsp;nbsp;Printer sheet drawernbsp;. UNSPSC Code. UNSPSC Codenbsp;:nbsp;nbsp;44101700nbsp;

30G0804 - Lexmark T65X 2000 Sheet High Capacity Input Drawer - 2000 Sheet $457.67 [U42153] UPC: 734646081191 UNSPC: 44101705 42.8 LB

Hewlett Packard CC423A Hp Color Laserjet 3X500 Input Device $2045.29 HP 3X500SHEET PAPER FEEDER AND STAND PROVIDES 1500 SHEET INPUT CAPACITY. Primary Information. Product Typenbsp;:nbsp;nbsp;Paper Feedernbsp;. For Use Withnbsp;:nbsp;nbsp;Color LaserJet Enterprise CP4520 Printer Seriesnbsp;. DimensionsMiscellaneous. Widthnbsp;:nbsp;nbsp;25.23 Inchnbsp;. Depthnbsp;:nbsp;nbsp;25.63 Inchnbsp;. Heightnbsp;:nbsp;nbsp;37.95 Inchnbsp;. ServiceSupport. Service Support Typenbsp;:nbsp;nbsp;Oneyear; nextday; onsite warrantynbsp;. Special Feature. COOnbsp;:nbsp;nbsp;Chinanbsp;. Discontinue Datenbsp;:nbsp;nbsp;:09/01/2012nbsp;. UNSPSC Code. UNSPSC Codenbsp;:nbsp;nbsp;44101700nbsp;

Lexmark 47B0110 Sheet Drawer $412.99 1 21 lb 47B0110 47B0110 Sheet Drawer 5.24" Height x 22.24" Width x 20.16" Depth 550 550 Sheet Lexmark Printers: C792DE C792DTE C792E X792DE X792DTE X792DTFE X792DTME X792DTPE X792DTSE This drawer will help optimize your paper input Paper size, paper and tray-present and tray-low sensing are supported The optional caster base is required when the product is configured with additional drawers, the high capacity feeder or the spacer when used floor standing Card Stock China Label Lexmark Lexmark International, Inc Paper - 60 g/m² to 176 g/m² Plain Paper Sheet Sheet Drawer www.lexmark.com

250-SHEET INPUT TRAY FOR $127.99 250-SHEET INPUT TRAY FOR

Manual Trans Input Shaft $347.99 Manual Trans Input Shaft;

Input Matters in SLA $59.95 Input Matters in SLA

Foreign Language Input $54.95 Foreign Language Input

This entry was posted on Friday, February 19th, 2010 at 10:55 pm and is filed under Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.