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Acidic paper is paper which was manufactured using acidic substances. [1] Widely used since the mid-nineteenth century, its pages become yellow within years, extremely brittle over decades, and eventually unreadable in the library and archive collections intended to preserve them. [2] This process has been called "slow fire".
The company Hercules Incorporated developed the first alkaline sizing in the 1950s that made acid-free paper possible. [10] Despite the advances in paper making and the identification of and concern around the brittle book problem, it took decades before the adoption of ANSI NISO Standard Z39.48-1984 - Permanence of Paper for Publications and Documents in Libraries in 1984.
The scion of the same blue-blood family that produced President Franklin Delano Roosevelt, Griffiths was the psychedelic counterculture's dream spokesman: a clean-cut "scientist's scientist," so ...
Paper Coating 1) The paper or board 2) The first layer of coating to even out the surface 3) A second layer for an even smoother and whiter surface. Pigments that absorb in the yellow and red part of the visible spectrum can be added. As the dye absorbs light, the brightness of the paper will decrease, unlike the effect of an optical ...
The causes of foxing are not well understood. One conjecture is that foxing is caused by a fungal growth on the paper. [8] Another is that foxing is caused by the effect on certain papers of the oxidation of iron, copper, or other substances in the pulp or rag from which the paper was made. [9] It is possible that multiple factors are involved.
Paper is a thin nonwoven material traditionally made from a combination of milled plant and textile fibres. The first paper-like plant-based writing sheet was papyrus in Egypt, but the first true papermaking process was documented in China during the Eastern Han period (25–220 AD), traditionally attributed to the court official Cai Lun.
Elution then is the process of removing analytes from the adsorbent by running a solvent, called an eluent, past the adsorbent–analyte complex. As the solvent molecules "elute", or travel down through the chromatography column, they can either pass by the adsorbent–analyte complex or displace the analyte by binding to the adsorbent in its ...
Blood is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume), [2] and contains proteins, glucose, mineral ions, and hormones. The blood cells are mainly red blood cells (erythrocytes), white blood cells (leukocytes), and (in mammals) platelets (thrombocytes). [3]