flattening

flattening

See oblateness.

Collins Dictionary of Astronomy © Market House Books Ltd, 2006

flattening

[′flat·ən·iŋ]

(geodesy)

The ratio of the difference between the equatorial and polar radii of the earth; the flattening of the earth is the ellipticity of the spheroid; the magnitude of the flattening is sometimes expressed as the numerical value of the reciprocal of the flattening. Also known as compression.

(metallurgy)

Straightening of metal sheet by passing it through special rollers which flatten it without changing its thickness. Also known as roll flattening.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

flattening

The ratio of the difference between the equatorial radius (major semi-axis) and the polar radius (minor semi-axis) of the earth to the equatorial radius. Also called compression. The flattening of the earth is the ellipticity of the spheroid, and it equals the ellipticity of the ellipse forming a meridianal section of the spheroid. If a and b represent the major and minor semi-axes of the spheroid, respectively, and f is the flattening of the earth, f= (a – b)/a. The magnitude of the flattening is sometimes expressed by stating the numerical value of the reciprocal of the flattening, a/(a – b).

An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved

flatten layers

To bring all levels of a multi-layered image down to one plane. High-end graphics programs provide a multi-layer file format, such as the Photoshop Document (PSD), which enables elements in each layer to be manipulated independently. In order to save the layered image in a single-layer graphics format such as TIFF or JPEG, the image is said to be "flattened."

An Adobe PDF file is also flattened to remove a transparency layer when the document is rendered in a printer or in an application that does not support the additional layer. See layers and PSD.

Copyright © 1981-2025 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Flattening

 

a means of producing thin metal strip, with a width-to-thickness ratio not exceeding 15, mainly by cold rolling gauged round wire in smooth rollers. Multistand continuous rolling mills and single-stand two-roller and multiple-roller mills with rollers 5–250 mm in diameter, made from very hard steels, are used for the flattening of metals. On a smaller industrial scale, ultrasonic forging devices are also used.

The main advantage of flattened strip (thickness, 0.005–1 mm; width, 0.05–15 mm) over strip produced by longitudinal cutting of cold-rolled bands is the roundness of the edges, which significantly improves the performance characteristics of items. In addition, in flattened strip the dimesional precision is higher and the surface quality is better. Such strip is used in manufacturing precision springs (including watch springs), electrical resistors, elastic elements of high-frequency oscillographic galvanometers, and special sewing needles.

REFERENCE

Prokatnoe proizvodstvo: Spravochnik, fasc. 1. Moscow, 1962.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.