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Fold Number
Fold number refers to how many double folds that are required to cause rupture of a paper test piece under standardized conditions. Fold number is defined in ISO 5626:1993 as the antilogarithm of the mean folding endurance: f=\text_ \frac=10^ where ''f'' is the fold number, ''Fi'' is the folding endurance for each test piece and ''n'' is total number of test pieces used. In the introduction of ISO 5626:1993 it is emphasized that fold number, as defined in that very International Standard, does not equal the mean number of double folds observed. The latter is however still the definition used in some countries.ISO 5626:1993 Paper – Determination of folding endurance, Introduction. If the numerical value of the folding endurance is not rounded off, these will however be equal. In the former Swedish standard SS 152005 ("Pappersordlista") from 1992, with paper related terms defined in Swedish and English, fold number is explained as "the number of double folds which a test stri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double Fold
''Double Fold: Libraries and the Assault on Paper'' is a non-fiction book by Nicholson Baker that was published in April 2001. An excerpt appeared in the July 24, 2000 issue of ''The New Yorker'', under the title "Deadline: The Author's Desperate Bid to Save America's Past." This exhaustively researched work (there are 63 pages of endnotes and 18 pages of references in the paperback edition) details Baker's quest to uncover the fate of thousands of books and newspapers that were replaced and often destroyed during the microfilming boom of the 1980s and 1990s. ''Double Fold'' is a controversial work and is not meant to be objective. In the preface, Baker says, "This isn't an impartial piece of reporting", (preface p. x) and ''The New York Times'' characterized the book as a "blistering and thoroughly idiosyncratic attack". Overview The term "double fold" refers to the test used by many librarians and preservation administrators to determine the brittleness and "usability" of paper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antilogarithm
In mathematics, the logarithm is the inverse function to exponentiation. That means the logarithm of a number to the base is the exponent to which must be raised, to produce . For example, since , the ''logarithm base'' 10 of is , or . The logarithm of to ''base'' is denoted as , or without parentheses, , or even without the explicit base, , when no confusion is possible, or when the base does not matter such as in big O notation. The logarithm base is called the decimal or common logarithm and is commonly used in science and engineering. The natural logarithm has the number e (mathematical constant), as its base; its use is widespread in mathematics and physics, because of its very simple derivative. The binary logarithm uses base and is frequently used in computer science. Logarithms were introduced by John Napier in 1614 as a means of simplifying calculations. They were rapidly adopted by navigators, scientists, engineers, surveyors and oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Folding Endurance
In paper testing, folding endurance is defined as the logarithm (to the base of ten) of the number of double folds that are required to make a test piece break under standardized conditions:ISO 5626:1993 Paper – Determination of folding endurance, 3.2. :''F'' = log10 ''d'', where ''F'' is the folding endurance and ''d'' the number of double folds. Folding endurance is especially applicable for papers used for maps, bank notes, archival documents, etc. The direction of the grain in relation to the folding line, the type of fibres used, the fibre contents, the calliper of the test piece, etc., as well as which type of folding tester that is used affect how many double folds a test piece can take. Folding endurance must not be confused with the related term fold number. Standards on folding endurance *ISO 5626: Paper – Determination of folding endurance. *TAPPI Test Method T 511: Folding endurance of paper (MIT tester). *TAPPI Test Method T 423: Folding endurance of pap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double Fold
''Double Fold: Libraries and the Assault on Paper'' is a non-fiction book by Nicholson Baker that was published in April 2001. An excerpt appeared in the July 24, 2000 issue of ''The New Yorker'', under the title "Deadline: The Author's Desperate Bid to Save America's Past." This exhaustively researched work (there are 63 pages of endnotes and 18 pages of references in the paperback edition) details Baker's quest to uncover the fate of thousands of books and newspapers that were replaced and often destroyed during the microfilming boom of the 1980s and 1990s. ''Double Fold'' is a controversial work and is not meant to be objective. In the preface, Baker says, "This isn't an impartial piece of reporting", (preface p. x) and ''The New York Times'' characterized the book as a "blistering and thoroughly idiosyncratic attack". Overview The term "double fold" refers to the test used by many librarians and preservation administrators to determine the brittleness and "usability" of paper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paper
Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distributed on the surface, followed by pressing and drying. Although paper was originally made in single sheets by hand, almost all is now made on large machines—some making reels 10 metres wide, running at 2,000 metres per minute and up to 600,000 tonnes a year. It is a versatile material with many uses, including printing, painting, graphics, signage, design, packaging, decorating, writing, and cleaning. It may also be used as filter paper, wallpaper, book endpaper, conservation paper, laminated worktops, toilet tissue, or currency and security paper, or in a number of industrial and construction processes. The papermaking process developed in east Asia, probably China, at least as early as 105 CE, by the Han court eunuch Cai Lun, although the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
