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Conservation And Restoration Of Vinyl Discs
The conservation and restoration of vinyl discs refers to the preventive measures taken to defend against damage and slow degradation, and to maintain fidelity of singles, 12" singles, EP’s, and LP’s in 45 or 33⅓ rpm 10" disc recordings. Vinyl LP preservation is generally considered separate from conservation, which refers to the repair and stabilization of individual discs. Commonly practiced in major sound archives and research libraries that house large collections of audio recordings, it is also frequently followed by audiophiles and home record collectors. Because vinyl—a light plastic made up of polyvinyl chloride acetate copolymer, or PVC—is considered the most stable of analog recording media, it is seen as less a concern for deterioration than earlier sound recordings made from more fragile materials such as acetate, vulcanite, or shellac. This hardly means that vinyl recordings are infallible, however, and research—both expert and evidential—has sho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plastics
Plastics are a wide range of synthetic or semisynthetic materials composed primarily of polymers. Their defining characteristic, plasticity, allows them to be molded, extruded, or pressed into a diverse range of solid forms. This adaptability, combined with a wide range of other properties such as low weight, durability, flexibility, chemical resistance, low toxicity, and low-cost production, has led to their widespread use around the world. While most plastics are produced from natural gas and petroleum, a growing minority are produced from renewable resources like polylactic acid. Between 1950 and 2017, 9.2 billion metric tons of plastic are estimated to have been made, with more than half of this amount being produced since 2004. In 2023 alone, preliminary figures indicate that over 400 million metric tons of plastic were produced worldwide. If global trends in plastic demand continue, it is projected that annual global plastic production will exceed 1.3 billion tons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petroleum
Petroleum, also known as crude oil or simply oil, is a naturally occurring, yellowish-black liquid chemical mixture found in geological formations, consisting mainly of hydrocarbons. The term ''petroleum'' refers both to naturally occurring unprocessed crude oil, as well as to petroleum products that consist of refining, refined crude oil. Petroleum is a fossil fuel formed over millions of years from anaerobic decay of organic materials from buried prehistoric life, prehistoric organisms, particularly planktons and algae, and 70% of the world's oil deposits were formed during the Mesozoic. Conventional reserves of petroleum are primarily recovered by oil drilling, drilling, which is done after a study of the relevant structural geology, sedimentary basin analysis, analysis of the sedimentary basin, and reservoir characterization, characterization of the petroleum reservoir. There are also unconventional (oil & gas) reservoir, unconventional reserves such as oil sands and oil sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollutants
A pollutant or novel entity is a substance or energy introduced into the environment that has undesired effect, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like oil) or anthropogenic in origin (i.e. manufactured materials or byproducts). Pollutants result in environmental pollution or become of public health concern when they reach a concentration high enough to have significant negative impacts. A pollutant may cause long- or short-term damage by changing the growth rate of plant or animal species, or by interfering with resources used by humans, human health or wellbeing, or property values. Some pollutants are biodegradable and therefore will not persist in the environment in a long term. However, the degradation products of some pollutants are themselves pollutants such as DDE and DDD produced from the degradation of DDT. Pollution has widespread negative impact on the environment. When ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oils
An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) and lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated lipids that are liquid at room temperature. The general definition of oil includes classes of chemical compounds that may be otherwise unrelated in structure, properties, and uses. Oils may be animal, vegetable, or petrochemical in origin, and may be volatile or non-volatile. They are used for food (e.g., olive oil), fuel (e.g., heating oil), medical purposes (e.g., mineral oil), lubrication (e.g. motor oil), and the manufacture of many types of paints, plastics, and other materials. Specially prepared oils are used in some religious ceremonies and rituals as purifying agents. Etymology First attested in English 1176, the word ''oil'' comes from Old French ''oile'', from -4; we might wonder whether there's a point at which it's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parts Cleaning
Parts cleaning is a step in various industrial processes, either as preparation for surface finishing or to safeguard delicate components. One such process, electroplating, is particularly sensitive to part cleanliness, as even thin layers of oil can hinder coating adhesion. Cleaning methods encompass solvent cleaning, hot alkaline detergent cleaning, electro-cleaning, and acid etch. In industrial settings, the water-break test is a common practice to assess machinery cleanliness. This test involves thoroughly rinsing and vertically holding the surface. Hydrophobic contaminants, like oils, cause water to bead and break, leading to rapid drainage. In contrast, perfectly clean metal surfaces are hydrophilic and retain an unbroken sheet of water without beading or draining off. It is important to note that this test may not detect hydrophilic contaminants, but they can be displaced during the water-based electroplating process. Surfactants like soap can reduce the test's sensitivity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stylus
A stylus is a writing utensil or tool for scribing or marking into softer materials. Different styluses were used to write in cuneiform by pressing into wet clay, and to scribe or carve into a wax tablet. Very hard styluses are also used to Engraving, engrave metal, and the slate and stylus system is used to punch out dots to write in Braille. Styluses are held in the hand and thus are usually a narrow elongated shape, similar to a modern ballpoint pen. Many styluses are heavily curved to be held more easily. The word ''stylus'' is also used to describe Stylus (computing), computer styluses used to assist in navigating or providing more precision when using touchscreens. Etymology ''Stylus'' comes from the Latin —the spelling ''stylus'' arose from an erroneous connection with Greek (), 'pillar'.''Oxford Latin Dictionary'', s.v. "stilus" (2012). The Latin word had several meanings, including "a long, sharply pointed piece of metal; the stem of a plant; a pointed instrume ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phonograph
A phonograph, later called a gramophone, and since the 1940s a record player, or more recently a turntable, is a device for the mechanical and analogue reproduction of sound. The sound vibration Waveform, waveforms are recorded as corresponding physical deviations of a helical or spiral groove engraved, etched, incised, or impressed into the surface of a rotating cylinder or disc, called a ''Phonograph record, record''. To recreate the sound, the surface is similarly rotated while a playback #Stylus, stylus traces the groove and is therefore vibrated by it, faintly reproducing the recorded sound. In early acoustic phonographs, the stylus vibrated a Diaphragm (acoustics), diaphragm that produced sound waves coupled to the open air through a flaring Horn loudspeaker, horn, or directly to the listener's ears through stethoscope-type earphones. The phonograph was invented in 1877 by Thomas Edison; its use would rise the following year. Alexander Graham Bell's Volta Laboratory an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preventive Maintenance
The technical meaning of maintenance involves functional checks, servicing, repairing or replacing of necessary devices, equipment, machinery, building infrastructure and supporting utilities in industrial, business, and residential installations. Terms such as "predictive" or "planned" maintenance describe various cost-effective practices aimed at keeping equipment operational; these activities occur either before or after a potential failure. Definitions Maintenance functions can be defined as maintenance, repair and overhaul (MRO), and MRO is also used for maintenance, repair and operations. Over time, the terminology of maintenance and MRO has begun to become standardized. The United States Department of Defense uses the following definitions: Federal Standard 1037C and from MIL-STD-188 and from the Department of Defense Dictionary of Military and Associated Terms * Any activity—such as tests, measurements, replacements, adjustments, and repairs—intended to retain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guidelines
A guideline is a statement by which to determine a course of action. It aims to streamline particular processes according to a set routine or sound practice. They may be issued by and used by any organization (governmental or private) to make the actions of its employees or divisions more predictable, and presumably of higher quality. A guideline is similar to a wikt:rule, rule, but are legally less binding as justified deviations are possible. List of guidelines Examples of guidelines are: * Ethical code#Code of practice .28professional ethics.29, Code of practice * EASE Guidelines for Authors and Translators of Scientific Articles * Federal Sentencing Guidelines * Guidelines for Examination in the European Patent Office * Guideline (medical), Medical guidelines * Publicly Available Specification * Programming style, Programming style guidelines * UNGEGN Toponymic Guidelines References Government documents Rules Standards {{Measurement-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Library Of Canada
Library and Archives Canada (LAC; ) is the federal institution tasked with acquiring, preserving, and providing accessibility to the documentary heritage of Canada. The national archive and library is the 16th largest library in the world. The LAC reports to the Parliament of Canada through the Minister of Canadian Heritage. LAC traces its origins to the Dominion Archives, formed in 1872, and the National Library of Canada, formed in 1953. The former was later renamed as the Public Archives of Canada in 1912, and the National Archives of Canada in 1987. In 2004, the National Archives of Canada and the National Library of Canada were merged to form Library and Archives Canada. History Predecessors The Dominion Archives was founded in 1872 as a division within the Department of Agriculture tasked with acquiring and transcribing documents related to Canadian history. In 1912, the division was transformed into an autonomous organization, Public Archives of Canada, with the new ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Recording
In digital recording, an audio signal, audio or video signal is converted into a stream of discrete numbers representing the changes over time in air pressure for audio, or Color, chroma and luminance values for video. This number stream is saved to a storage device. To play back a digital recording, the numbers are retrieved and converted back into their original analog signal, analog audio or video forms so that they can be heard or seen. In a properly matched analog-to-digital converter (ADC) and digital-to-analog converter (DAC) pair, the analog signal is accurately reconstructed, within the constraints of the Nyquist–Shannon sampling theorem, which dictates the sampling rate and quantization error dependent on the Audio bit depth, audio or Bit depth (computer graphics), video bit depth. Because the signal is stored digitally, assuming proper error detection and correction, the recording is not degraded by copying, storage or interference. Timeline *October 3, 1938: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
