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Diazo Copy
Whiteprint describes a document reproduction produced by using the diazo chemical process. It is also known as the blue-line process since the result is blue lines on a white background. It is a contact printing process which accurately reproduces the original in size, but cannot reproduce continuous tones or colors. The light-sensitivity of the chemicals used was known in the 1890s and several related printing processes were patented at that time. Whiteprinting replaced the blueprint process for reproducing architectural and engineering drawings because the process was simpler and involved fewer toxic chemicals. A blue-line print is not permanent and will fade if exposed to light for weeks or months, but a drawing print that lasts only a few months is sufficient for many purposes. The diazo printing process Two components underpin diazo printing:{{Ullmann , doi=10.1002/14356007.o13_o08.pub2, title=Imaging Technology, 2. Copying and Nonimpact Printing Processes, last1=Pai, first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkaline
In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a base (chemistry), basic, ionic compound, ionic salt (chemistry), salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The adjective alkaline, and less often, alkalescent, is commonly used in English language, English as a synonym for basic, especially for bases soluble in water. This broad use of the term is likely to have come about because alkalis were the first bases known to obey the acid-base reaction theories#Arrhenius theory, Arrhenius definition of a base, and they are still among the most common bases. Etymology The word "alkali" is derived from Arabic ''al qalīy'' (or ''alkali''), meaning ''the calcined ashes'' (see calcination), referring to the original source of alkaline substances. A water-extract of burned plant ashes, called potash and composed mostly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ozalid
Ozalid is a registered trademark of a type of paper used for "test prints" in the monochrome classic offset process. The word "Ozalid" is an anagram of "diazol", the name of the substance that the company "Ozalid" used in the fabrication of this type of paper. Overview ''OZALID'' was first federally registered in the United States as a trademark on February 5, 1929 as a brand for ''light-sensitive copying and photographic papers.'' The registration currently is owned by R.Q.O. Holding Company, Inc. of New York, and is related to the even earlier registration of October 11, 1923 in what is now the Federal Republic of Germany. The R.Q.O. Holding Company also owns a United States trademark registration for ''OZALID'' for "copying and reprographic machines, apparatus and parts thereof." However, compound "Ozalid Process" appears never to have been registered as a trademark, and the use of ''OZALID'' specifically for the Ozalid process using diazo compound paper is ''not'' currently ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heliographic Copier
A heliographic copier or heliographic duplicator is an apparatus used in the world of reprography for making contact prints on paper from original drawings made with that purpose on tracing paper, parchment paper or any other transparent or translucent material using different procedures. In general terms some type of ''heliographic copier'' is used for making: Hectographic prints, Ferrogallic prints, Gel-lithographs or Silver halide prints. All of them, until a certain size, can be achieved using a contact printer with an appropriate lamp (ultraviolet, etc...) but for big engineering and architectural plans, the ''heliographic copiers'' used with the cyanotype and the diazotype technologies, are of the roller type, which makes them completely different from contact printers. In the "argot" of engineers, architects and designers, the resulting plan copies coming from any type of '' heliographic copier'' no matter they were either blue or white, were traditionally called blueprints, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blueprint
A blueprint is a reproduction of a technical drawing or engineering drawing using a contact print process on light-sensitive sheets. Introduced by Sir John Herschel in 1842, the process allowed rapid and accurate production of an unlimited number of copies. It was widely used for over a century for the reproduction of specification drawings used in construction and industry. The blueprint process was characterized by white lines on a blue background, a negative of the original. The process was not able to reproduce color or shades of grey. The process is now obsolete. It was first largely displaced by the diazo whiteprint process, and later by large-format xerographic photocopiers. The term ''blueprint'' continues to be used less formally to refer to any floor plan (and even less formally, any type of plan). Practicing engineers, architects, and drafters often call them "drawings", “prints”, or “plans”. It has almost entirely been replaced with digital computer-aided ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azo Compound
Azo compounds are organic compounds bearing the functional group diazenyl (, in which R and R′ can be either aryl or alkyl groups). IUPAC defines azo compounds as: "Derivatives of diazene (diimide), , wherein both hydrogens are substituted by hydrocarbyl groups, e.g. azobenzene or diphenyldiazene." The more stable derivatives contain two aryl groups. The group is called an ''azo group'' (, ). Many textile and leather articles are dyed with azo dyes and pigments. Aryl azo compounds Aryl azo compounds are usually stable, crystalline species. Azobenzene is the prototypical aromatic azo compound. It exists mainly as the ''trans'' isomer, but upon illumination, converts to the ''cis'' isomer. Aromatic azo compounds can be synthesized by azo coupling, which entails an electrophilic substitution reaction where an aryl diazonium cation is attacked by another aryl ring, especially those substituted with electron-donating groups: :ArN2+ + Ar'H -> ArN=NAr' + H+ Since diazoniu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xerography
Xerography is a dry photocopying technique. Originally called electrophotography, it was renamed xerography—from the roots el, ξηρός, label=none ''xeros'', meaning "dry" and -γραφία ''-graphia'', meaning "writing"—to emphasize that unlike reproduction techniques then in use such as cyanotype, the process of xerography used no liquid chemicals. History Xerography was invented by American physicist Chester Carlson, based significantly on contributions by Hungarian physicist Pál Selényi. Carlson applied for and was awarded on October 6, 1942. Carlson's innovation combined electrostatic printing with photography, unlike the dry electrostatic printing process invented by Georg Christoph Lichtenberg in 1778. Carlson's original process was cumbersome, requiring several manual processing steps with flat plates. In 1946, Carlson signed an agreement with Haloid Photographic Company to develop it as a commercial product. Before that year, Carlson had proposed his ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incandescent Light
An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxidation. Current is supplied to the filament by terminals or wires embedded in the glass. A bulb socket provides mechanical support and electrical connections. Incandescent bulbs are manufactured in a wide range of sizes, light output, and voltage ratings, from 1.5 volts to about 300 volts. They require no external regulating equipment, have low manufacturing costs, and work equally well on either alternating current or direct current. As a result, the incandescent bulb became widely used in household and commercial lighting, for portable lighting such as table lamps, car headlamps, and flashlights, and for decorative and advertising lighting. Incandescent bulbs are much less efficient than other types of electric lighting, converting less ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonia
Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous waste, particularly among aquatic organisms, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to 45% of the world's food and fertilizers. Around 70% of ammonia is used to make fertilisers in various forms and composition, such as urea and Diammonium phosphate. Ammonia in pure form is also applied directly into the soil. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceutical products and is used in many commercial cleaning products. It is mainly collected by downward displacement of both air and water. Although common in nature—both terrestrially and in the outer planets of the Solar System—and in wide use, ammonia is both caust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sepia (color)
Sepia is a reddish-brown color, named after the rich brown pigment derived from the ink sac of the common cuttlefish ''Sepia''. The word ''sepia'' is the Latinized form of the Greek σηπία, ''sēpía'', cuttlefish. In the visual arts Sepia ink was commonly used for writing in Greco-Roman civilization. It remained in common use as an artist's drawing material until the 19th century. Grisaille is a painting technique developed in the 14th century in which a painting is rendered solely in tones of gray, sepia, or dark green. In the last quarter of the 18th century, Professor Jacob Seydelmann of Dresden developed a process to extract and produce a concentrated form of sepia for use in watercolors and oil paints. Sepia toning is a chemical process used in photography which changes the appearance of black-and-white prints to brown. The color is now often associated with antique photographs. Most photo graphics software programs and many digital cameras include a sepia tone filte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonium Hydroxide
Ammonia solution, also known as ammonia water, ammonium hydroxide, ammoniacal liquor, ammonia liquor, aqua ammonia, aqueous ammonia, or (inaccurately) ammonia, is a solution of ammonia in water. It can be denoted by the symbols NH3(aq). Although the name ammonium hydroxide suggests an alkali with chemical formula, composition , it is actually impossible to isolate samples of NH4OH. The ions and OH− do not account for a significant fraction of the total amount of ammonia except in extremely dilute solutions. Basicity of ammonia in water In aqueous solution, ammonia deprotonation, deprotonates a small fraction of the water to give ammonium and hydroxide according to the following chemical equilibrium, equilibrium: : NH3 + H2O NH4+ + OH−. In a 1 Molar concentration, M ammonia solution, about 0.42% of the ammonia is converted to ammonium, equivalent to pH = 11.63 because [NH4+] = 0.0042 M, [OH−] = 0.0042 M, [NH3] = 0.9958 M, and pH = 14 + log10[OH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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