Postage stamp

Many countries have cele brated their chemical indus try on postage stamps The stamp shown was issued in 1971 by Argentina... 

A DNA double helix as pic tured on a 1964 postage stamp issued by Israel... 

Starch pyrodextrins and British gums have the abiUty, in aqueous dispersion, to form films capable of bonding like or unlike materials. Thus, they have uses as adhesives for envelopes, postage stamps, and other products. These dextrins are used in glass-fiber siting to protect the extmded fiber from abrasion, and as binders for metal core castings, water color paints, briquettes, and many other composite materials (qv). 

Frei-marke, /. postage stamp, -mut, m. frankness, sincerity, -sein, n. free state, freedom, frei-sinnig, a. large-minded liberal, -spre-chen, v.t. acquit dispense. 

As for miniaturisation, examples are UV/VIS spectrometers using a linearly variable filter rather than a diffraction grating as the wavelength separation device (matchbox size), and double-focusing mass sensors (postage stamp size). 

Fig. 12.2 A foldable, bendable battery paper invention which can be inserted under the skin as a pacemaker and powered in part by bodily fluids, (a) A postage-stamp-sized battery as thin as paper, (b) the flexible nanocomposite film battery used to glow a red light-emitting diode (LED)...

Recently, our laboratory produced a foldable, bendable, and cutable postage-stamp-sized battery (Fig. 12.2). The device looks like a simple sheet of black paper, but it could spell a revolution in implantable battery technology (Pushparaj et al., 2007). The paper battery, a one-piece-integrated device is made of cellulose with CNT and lithium electrodes. The device is flexible, rechargeable, and has the ability to function over a wide range of temperatures giving it a wide variety of potential biomedical applications. As a biomaterial, this paper battery may be useful as a pacemaker because it could easily be inserted under a patient s skin. 

There are only a few commercial uses for europium. Europium oxide, (Eu O ), a compound of europium, is added to infra-sensitive phosphors to enhance the red colors on TV and computer-monitor picture tubes. It is also added to fluorescent light tubes to increase their efflciency, as well as to some materials to make lasers. Since it is a good neutron absorber, it is part of nuclear reactor control rods. Europium is an additive to the glue used on postage stamps, thus making it possible for the electronic sorting machines in U.S. postal offices to read the stamps. 

Borman, S. (1993). Black chemist Percy Julian commemorated on postage stamp. Chemical Engineering News (February 1), 9—12. 

In 1934, in honor of the centenary of Mendeleev s birth, the U.S.S.R. issued a set of four denominations of commemorative postage stamps bearing a handsome portrait against a background of the periodic table. Reproductions of two of these stamps appeared in the Journal of Chemical Education in July of that year. 

Victor Goldschmidt, as pictured on a Norwegian postage stamp issued in 1974. 

Figure 20-15 Schematic representation of a charge coupled device, (a) Cross-sectional view, indicating charge generation and storage in each pixel. ( >) Top view, showing two-dimensional nature of an array. An actual array is about the size of a postage stamp.

Depctrins, products of the partial hydrolysis of starch, are polysacchandes of lower molecular weight than starch. They are used in infant food because they are easier to digest than starches. Dextrins are sticky when wet and are used as mucilage on postage stamps and envelopes. 

Less commonly, white LSD powder is squeezed into tiny pills (called microdots) or placed in capsules. It can also be formed into clear gelatin squares called window panes. In the 1990s, LSD has turned up at raves in blue-colored gel wraps that look like bubble-wrap packing material and in small breath freshener-type spray bottles. LSD has also been found on or in postage stamps, cookies, drinks, sugar cubes, and commercially produced candies. 

Autographed British Postage stamp honouring Nobel Laureate, Professor Derek Barton... 

PVP is short for the polymer poly (vinyl pyrrolidone).1021 When PVP is left in the open air it absorbs around 15% of its weight as water from the air, such is its ability to cling to water molecules. It is also used in various personal care products like shampoos, toothpastes, and is the adhesive which has replace animal-based glues on envelopes and postage stamps. 

For example, poly(vinyl alcohol) (PVOH) finds application as an effective adhesive for paper products such as the old-fashioned postage stamps or envelopes. Licking the stamp or envelope flap causes the adhesive to become sticky because water plasticizes the PVOH and lowers the Tg below room temperature. On pressing the stamp to a piece of paper, the polymer chains can entangle and hydrogen bond with the cellulose in the paper. As the water... 

The cost of first-class postage stamps continues to rise every few years, however, the price is still a be... 

The mechanism of olfaction has many theories but is not fully understood and is still the subject of research. The nose is the human organ that detects smell (Fig. 5.9). It extends from the face to the end of the palate. In its simplest explanation the two nasal cavities are lined with a mucous membrane, kept moist by the secreted substance mucus. Chemicals in the air entering the nose must dissolve in this mucus before they can be detected. A small area - about the size of a small postage stamp - in the upper part of the nasal cavity contains olfactory cells, which are sensitive to the chemicals in the mucus solution. For a molecule to be detected it must bind specifically to the sensitive cells that act as sensory receptors. The sensory receptors situated in the olfactory epithelium (epithelium is the name given to the outer layer of covering cells) are believed to bind specifically with substances according to the shape of their molecules. 

Friedrich August Kekule von Stradoniz (1829-1896), pictured on a Belgian postage stamp. 

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