|
Whiteprint
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 that accurately reproduces a translucent original in size, but can reproduce only limited tonal range and no color. 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 around the turn of the 20th century 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 print that lasts only a few months was sufficient as a working drawing for many purposes, and the original vellum drawings could be stored and reprinted as needed. Whiteprinting became obsolete around the turn of the 21st ... [...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 Architectural drawing#Working drawings, construction and industry. Blueprints were characterized by white lines on a blue background, a Negative (photography), negative of the original. Color or shades of grey could not be reproduced. The process is obsolete, initially superseded by the whiteprint#The_diazo_printing_process, diazo-based ''whiteprint'' process, and later by large-format xerography, xerographic photocopiers. It has since almost entirely been superseded by digital computer-aided construction drawings. The term ''wikt:blueprint, blueprint'' continues to be used informally to refer to any floor plan (and by analogy, wikt:blu ... [...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 bluepri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engineering Drawing
An engineering drawing is a type of technical drawing that is used to convey information about an object. A common use is to specify the geometry necessary for the construction of a component and is called a detail drawing. Usually, a number of drawings are necessary to completely specify even a simple component. These drawings are linked together by a "master drawing." This "master drawing" is more commonly known as an assembly drawing. The assembly drawing gives the ''drawing numbers'' of the subsequent detailed components, quantities required, construction materials and possibly 3D images that can be used to locate individual items. Although mostly consisting of pictographic representations, Engineering drawing abbreviations and symbols, abbreviations and symbols are used for brevity and additional textual explanations may also be provided to convey the necessary information. The process of producing engineering drawings is often referred to as technical drawing or drafting ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heliographic Copy
In solar observation and imaging, coordinate systems are used to identify and communicate locations on and around the Sun. The Sun is made of plasma, so there are no permanent demarcated points that can be referenced. Background The Sun is a rotating sphere of plasma at the center of the Solar System. It lacks a solid or liquid surface, so the interface separating its interior and its exterior is usually defined as the boundary where plasma becomes opaque to visible light, the photosphere. Since plasma is gaseous in nature, this surface has no permanent demarcated points that can be used for reference. Furthermore, its rate of rotation varies with latitude, rotating faster at the equator than at the poles. Cardinal directions In observations of the solar disk, cardinal directions are typically defined so that the Sun's northern and southern hemispheres point toward Earth's northern and southern celestial poles, respectively, and the Sun's eastern and western hemispheres point ... [...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 a Salt (chemistry), salt with the chemical formula, composition , it is 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. The concentration of such solutions is measured in units of the Baumé scale (density), with 26 degrees Baumé (about 30% of ammonia by weight at ) being the typical high-concentration commercial product. 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 ⇌ + OH−. In a 1 Molar concentra ... [...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] |
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.", where Ph stands for phenyl group. 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 urinary tract infections">Phenazopyridine, an aryl azo compound, is used to treat urinary tract infections">150px Aryl azo compounds are usually stable, crystalline species. Azobenzene is the prototypical aromatic azo compound. It exists mainly as the Cis-trans isomerism, ''trans'' isomer, but upon illumination, converts to the Cis-trans isomerism, ''cis'' isomer. Aromatic azo compounds can be synthesized by azo coupling, which entails an electrophilic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xerography
Xerography is a dry photocopying technique. Originally called electrophotography, it was renamed xerography—from the Greek roots , meaning "dry" and , 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 idea to more than a dozen companies, but none was int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incandescent Light
An incandescent light bulb, also known as an incandescent lamp or incandescent light globe, is an electric light that produces illumination by Joule heating a #Filament, filament until it incandescence, glows. The filament is enclosed in a glass bulb that is either vacuum, evacuated or filled with inert gas to protect the filament from oxidation. Electric 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 Regulator (automatic control), 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, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonia
Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pungent smell. It is widely used in fertilizers, refrigerants, explosives, cleaning agents, and is a precursor for numeous chemicals. Biologically, it is a common nitrogenous waste, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to fertilisers. Around 70% of ammonia produced industrially 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 chemicals. In many countries, it is classified as an List of extremely hazardous substances, extremely hazardous substance. Ammonia is toxic, cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
