na

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NA

The two-character ISO 3166 country code for NAMIBIA.
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na

Used in bond transaction tables in newspapers to indicate a bond that trades on a nonaccrual basis (that is, on the basis of no obligation to repay any back interest owed).
Wall Street Words: An A to Z Guide to Investment Terms for Today's Investor by David L. Scott. Copyright © 2003 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved. All rights reserved.
References in periodicals archive ?
Numerical aperture: A calculation that shows the ability of an objective lens to make fine structural detail in the specimen distinct (N.A.
Researchers have also begun to seek options for a fourth-generation optical recording medium that could be based on near-field optics (with a numerical aperture of 1.4 or even 2).
These systems offer the advantage of polymeric material with no low molecular weight additives, a controlled numerical aperture up to about 0.25 and low moisture absorption.
As might be guessed by looking at the markings on any objective lens, the magnification and numerical aperture are important for the image-formation properties of an optical microscope.
In this case, transverse resolution is not defined through the numerical aperture NA of the fiber, and consequently, through Rayleigh limit (about 0.6[lambda]/NA).
An angle of 30[degrees] is at the edge of a solid angle corresponding to a numerical aperture (NA) of 0.5.
Numerical aperture refers to the light gathering ability plus the resolving power of the lens.
1 A 100 Mb/s multimode optical fiber data link, up to 2 km, taken from the FDDI physical medium dependent specifications: Nominal core diameter: 62.5 Cladding diameter: 125.0 [+ or -] 3.0 Modal bandwidth (1,300 nm): 500 MHz/km Attentuation for link, including component loss (1,300 nm): 11.0 dB Nominal numerical aperture: 0.275
With active cooling, the 2400B-405 model can emit greater than 20W from a 7.5mm diameter clear aperture with a 0.66 numerical aperture (NA).
They are also available in higher numerical aperture designs.
A phase ring has been incorporated into the microscope's body to speed the attachment of high numerical aperture objectives and to prevent light loss.

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