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Spirit Duplicator
A spirit duplicator (also referred to as a Rexograph or Ditto machine in North America, Banda machine in the UK, Gestetner machine in Australia) is a printing method invented in 1923 by Wilhelm Ritzerfeld that was commonly used for much of the rest of the 20th century. The term "spirit duplicator" refers to the alcohols that were a major component of the solvents used as "inks" in these machines. The device coexisted alongside the mimeograph. Spirit duplicators were used mainly by schools, churches, clubs, and other small organizations, such as in the production of fanzines, because of the limited number of copies one could make from an original, along with the low cost (and corresponding low quality) of copying. History The spirit duplicator was invented in 1923 by Wilhelm Ritzerfeld. The best-known manufacturer in the United States and the world was Ditto Corporation of Illinois. Copiers in the United Kingdom were commonly manufactured by Associated Automation Ltd of Willes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Printing
Printing is a process for mass reproducing text and images using a master form or template. The earliest non-paper products involving printing include cylinder seals and objects such as the Cyrus Cylinder and the Cylinders of Nabonidus. The earliest known form of printing as applied to paper was woodblock printing, which appeared in China before 220 AD for cloth printing. However, it would not be applied to paper until the seventh century.Shelagh Vainker in Anne Farrer (ed), "Caves of the Thousand Buddhas", 1990, British Museum publications, Later developments in printing technology include the movable type invented by Bi Sheng around 1040 AD and the printing press invented by Johannes Gutenberg in the 15th century. The technology of printing played a key role in the development of the Renaissance and the Scientific Revolution and laid the material basis for the modern knowledge-based economy and the spread of learning to the masses. History Woodblock printing Woodblock p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isopropyl Alcohol
Isopropyl alcohol (IUPAC name propan-2-ol and also called isopropanol or 2-propanol) is a colorless, flammable organic compound with a pungent alcoholic odor. As an isopropyl group linked to a hydroxyl group (chemical formula ) it is the simplest example of a secondary alcohol, where the alcohol carbon atom is attached to two other carbon atoms. It is a structural isomer of propan-1-ol and ethyl methyl ether. It is used in the manufacture of a wide variety of industrial and household chemicals and is a common ingredient in products such as antiseptics, disinfectants, hand sanitizer and detergents. Well over one million tonnes is produced worldwide annually. Properties Isopropyl alcohol is miscible in water, ethanol, and chloroform as, like these compounds, isopropyl is a polar molecule. It dissolves ethyl cellulose, polyvinyl butyral, many oils, alkaloids, and natural resins. Unlike ethanol or methanol, isopropyl alcohol is not miscible with salt solutions and can be separ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hectograph
The hectograph, gelatin duplicator or jellygraph is a printing process that involves transfer of an original, prepared with special inks, to a pan of gelatin or a gelatin pad pulled tight on a metal frame. While the original use of the technology has diminished, it has recently been revived for use in the art world. The hectograph has been modernized and made practical for anyone to use. Process The special aniline dyes for making the master image came in the form of ink or in pens, pencils, carbon paper and even typewriter ribbon. Hectograph pencils and pens are sometimes still available. Various other inks have been found usable to varying degrees in the process; master sheets for spirit duplicators have also been pressed into service. Unlike a spirit duplicator master, a hectograph master is not a mirror image. Thus, when using a spirit duplicator master with a hectograph, one writes on the back of the purple sheet, using it like carbon paper to produce an image on the whit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid-free Paper
Acid-free paper is paper that, if infused in water, yields a neutral or basic (chemistry), basic pH (7 or slightly greater). It can be made from any cellulose fiber as long as the active acid pulp is eliminated during processing. It is also lignin- and sulfur-free. Acid-free paper addresses the problem of Preservation (library and archival science), preserving documents and Conservation (cultural heritage), preserving artwork for long periods. Overview Paper made from wood-based pulp that has not had its lignin removed turns yellow, becomes brittle, and deteriorates over time. When exposed to light and/or heat, the molecules in the acidic paper will break down even faster. Acidic wood-pulp paper became commonplace in the late 19th century, and in the 1930s William Barrow (chemist), William Barrow (a chemist and librarian) published a report about the deterioration of acidic paper in the libraries. For fear of the gradual disintegration of written materials, measures have since ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorescent Lighting
A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow. A fluorescent lamp converts electrical energy into useful light much more efficiently than an incandescent lamp. The typical luminous efficacy of fluorescent lighting systems is 50–100 lumens per watt, several times the efficacy of incandescent bulbs with comparable light output. For comparison, the luminous efficacy of an incandescent bulb may only be 16 lumens per watt. Fluorescent lamp fixtures are more costly than incandescent lamps because, among other things, they require a ballast to regulate current through the lamp, but the initial cost is offset by a much lower running cost. Compact fluorescent lamps are now available in the same popular sizes as incandesc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultraviolet Light
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack the energy to ionize atoms, it can cause chemical reactions and causes many substances to glow or fluoresce. Consequently, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules. Short-wave ultraviolet light damages DNA and sterilizes surfaces with which it comes into contact. For h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archivist
An archivist is an information professional who assesses, collects, organizes, preserves, maintains control over, and provides access to Document, records and archives determined to have long-term value. The records maintained by an archivist can consist of a variety of forms, including letters, diaries, logs, other personal documents, government documents, sound and/or picture recordings, digital files, or other physical objects. Description As Richard Pearce-Moses wrote: Determining what records have enduring value can be challenging. Archivists must also select records valuable enough to justify the costs of storage and preservation, plus the labor-intensive expenses of arrangement, description, and reference service. The theory and scholarly work underpinning archives practices is called archival science. The most common related occupations are librarians, Curator, museum curators, and records managers. The occupation of archivist is distinct from that of librarian. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flash Point
The flash point of a material is the "lowest liquid temperature at which, under certain standardized conditions, a liquid gives off vapours in a quantity such as to be capable of forming an ignitable vapour/air mixture". (EN 60079-10-1) The flash point is sometimes confused with the autoignition temperature, the temperature that causes spontaneous ignition. The fire point is the lowest temperature at which the vapors keep burning after the ignition source is removed. It is higher than the flash point, because at the flash point vapor may not be produced fast enough to sustain combustion. Neither flash point nor fire point depends directly on the ignition source temperature, but ignition source temperature is far higher than either the flash or fire point. Fuels The flash point is a descriptive characteristic that is used to distinguish between flammable fuels, such as petrol (also known as gasoline), and combustible fuels, such as diesel. It is also used to characterize the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trichlorofluoromethane
Trichlorofluoromethane, also called freon-11, CFC-11, or R-11, is a chlorofluorocarbon (CFC). It is a colorless, faintly ethereal, and sweetish-smelling liquid that boils around room temperature. CFC-11 is a Class 1 ozone-depleting substance which damages Earth's protective stratospheric ozone layer. Historical use Trichlorofluoromethane was first widely used as a refrigerant. Because of its high boiling point (compared to most refrigerants), it can be used in systems with a low operating pressure, making the mechanical design of such systems less demanding than that of higher-pressure refrigerants R-12 or R-22. Trichlorofluoromethane is used as a reference compound for fluorine-19 NMR studies. Trichlorofluoromethane was formerly used in the drinking bird novelty, largely because it has a boiling point of . The replacement, dichloromethane, boiling point , requires a higher ambient temperature to work. Prior to the knowledge of the ozone depletion potential of chlorin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methanol
Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a light, volatile, colourless, flammable liquid with a distinctive alcoholic odour similar to that of ethanol (potable alcohol). A polar solvent, methanol acquired the name wood alcohol because it was once produced chiefly by the destructive distillation of wood. Today, methanol is mainly produced industrially by hydrogenation of carbon monoxide. Methanol consists of a methyl group linked to a polar hydroxyl group. With more than 20 million tons produced annually, it is used as a precursor to other commodity chemicals, including formaldehyde, acetic acid, methyl tert-butyl ether, methyl benzoate, anisole, peroxyacids, as well as a host of more specialised chemicals. Occurrence Small amounts of methanol are present in normal, healthy hu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pastel (color)
Pastels or pastel colors belong to a pale family of colors, which, when described in the HSV color space, have high value and low saturation. They are named after an artistic medium made from pigment and solid binding agents, similar to crayons. Pastel sticks historically tended to have lower saturation than paints of the same pigment, hence the name of the color family. The colors of this family are usually described as "soothing." Pastel colors are common in the kawaii aesthetic. Pink, mauve, and baby blue are commonly used pastel colors, as well as mint green, peach, periwinkle, and lavender. In fashion A form of goth style called ''pastel goth'' adds pastel colors to the usually monochrome palette of gothic fashion. Examples Gallery File:Gaiety pastels.jpg, Gaiety pastels File:Perles pastel.jpg, Pastel-colored bead A bead is a small, decorative object that is formed in a variety of shapes and sizes of a material such as stone, bone, shell, glass, plastic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm Ritzerfeld , the Dutch national anthem
{{Disambiguation ...
Wilhelm may refer to: People and fictional characters * William Charles John Pitcher, costume designer known professionally as "Wilhelm" * Wilhelm (name), a list of people and fictional characters with the given name or surname Other uses * Mount Wilhelm, the highest mountain in Papua New Guinea * Wilhelm Archipelago, Antarctica * Wilhelm (crater), a lunar crater See also * Wilhelm scream, a stock sound effect * SS ''Kaiser Wilhelm II'', or USS ''Agamemnon'', a German steam ship * Wilhelmus "Wilhelmus van Nassouwe", usually known just as "Wilhelmus" ( nl, Het Wilhelmus, italic=no; ; English translation: "The William"), is the national anthem of both the Netherlands and the Kingdom of the Netherlands. It dates back to at least 1572 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
