“A Standing Wave in the Web of Our Communications”: Usenet and the Socio-Technical Construction of Cyberspace Values

Author(s):  
Bryan Pfaffenberger
Author(s):  
O.L. Krivanek ◽  
J. TaftØ

It is well known that a standing electron wavefield can be set up in a crystal such that its intensity peaks at the atomic sites or between the sites or in the case of more complex crystal, at one or another type of a site. The effect is usually referred to as channelling but this term is not entirely appropriate; by analogy with the more established particle channelling, electrons would have to be described as channelling either through the channels or through the channel walls, depending on the diffraction conditions.


Author(s):  
G. Thomas ◽  
K. M. Krishnan ◽  
Y. Yokota ◽  
H. Hashimoto

For crystalline materials, an incident plane wave of electrons under conditions of strong dynamical scattering sets up a standing wave within the crystal. The intensity modulations of this standing wave within the crystal unit cell are a function of the incident beam orientation and the acceleration voltage. As the scattering events (such as inner shell excitations) that lead to characteristic x-ray production are highly localized, the x-ray intensities in turn, are strongly determined by the orientation and the acceleration voltage. For a given acceleration voltage or wavelength of the incident wave, it has been shown that this orientation dependence of the characteristic x-ray emission, termed the “Borrmann effect”, can also be used as a probe for determining specific site occupations of elemental additions in single crystals.


Author(s):  
Vijay Krishnamurthi ◽  
Brent Bailey ◽  
Frederick Lanni

Excitation field synthesis (EFS) refers to the use of an interference optical system in a direct-imaging microscope to improve 3D resolution by axially-selective excitation of fluorescence within a specimen. The excitation field can be thought of as a weighting factor for the point-spread function (PSF) of the microscope, so that the optical transfer function (OTF) gets expanded by convolution with the Fourier transform of the field intensity. The simplest EFS system is the standing-wave fluorescence microscope, in which an axially-periodic excitation field is set up through the specimen by interference of a pair of collimated, coherent, s-polarized beams that enter the specimen from opposite sides at matching angles. In this case, spatial information about the object is recovered in the central OTF passband, plus two symmetric, axially-shifted sidebands. Gaps between these bands represent "lost" information about the 3D structure of the object. Because the sideband shift is equal to the spatial frequency of the standing-wave (SW) field, more complete recovery of information is possible by superposition of fields having different periods. When all of the fields have an antinode at a common plane (set to be coincident with the in-focus plane), the "synthesized" field is peaked in a narrow infocus zone.


2008 ◽  
Vol 11 (2) ◽  
pp. 83-85
Author(s):  
Howard Wilson
Keyword(s):  

2005 ◽  
Vol 8 (1) ◽  
pp. 16-18
Author(s):  
Howard F. Wilson
Keyword(s):  

1999 ◽  
Vol 3 (2) ◽  
pp. 6-6
Author(s):  
Barbara Shadden
Keyword(s):  

1999 ◽  
Vol 3 (1) ◽  
pp. 3-3
Author(s):  
Barbara B. Shadden
Keyword(s):  

2008 ◽  
Vol 18 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Mark Kander ◽  
Steve White

Abstract This article explains the development and use of ICD-9-CM diagnosis codes, CPT procedure codes, and HCPCS supply/device codes. Examples of appropriate coding combinations, and Coding rules adopted by most third party payers are given. Additionally, references for complete code lists on the Web and a list of voice-related CPT code edits are included. The reader is given adequate information to report an evaluation or treatment session with accurate diagnosis, procedure, and supply/device codes. Speech-language pathologists can accurately code services when given adequate resources and rules and are encouraged to insert relevant codes in the medical record rather than depend on billing personnel to accurately provide this information. Consultation is available from the Division 3 Reimbursement Committee members and from [email protected] .


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