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28-454: From the beginning of 1961 to 1983, Vasa was housed in a temporary structure called Wasavarvet ("The Vasa Shipyard") where she was treated with polyethylene glycol . Visitors could only view the ship from two levels and the maximum distance was only 5 m (17 ft). In 1981, the Swedish government decided that a permanent Vasa museum was to be constructed and a competition for the design of

56-401: A PEG structure to another larger molecule, for example, a therapeutic protein , which is then referred to as a PEGylated protein. PEGylated interferon alfa-2a or alfa-2b are commonly used injectable treatments for hepatitis C infection. PEG is soluble in water , methanol , ethanol , acetonitrile , benzene , and dichloromethane , and is insoluble in diethyl ether and hexane . It

84-407: A distribution of molecular weights (i.e. they are polydisperse). The size distribution can be characterized statistically by its weight average molecular weight ( M w ) and its number average molecular weight ( M n ), the ratio of which is called the polydispersity index ( Đ M ). M w and M n can be measured by mass spectrometry . PEGylation is the act of covalently coupling

112-667: A few hours. Polyethylene oxide, or high-molecular-weight polyethylene glycol, is synthesized by suspension polymerization . It is necessary to hold the growing polymer chain in solution in the course of the polycondensation process. The reaction is catalyzed by magnesium-, aluminium-, or calcium-organoelement compounds. To prevent coagulation of polymer chains from solution, chelating additives such as dimethylglyoxime are used. Alkaline catalysts such as sodium hydroxide (NaOH), potassium hydroxide (KOH), or sodium carbonate (Na 2 CO 3 ) are used to prepare low-molecular-weight polyethylene glycol. Lubrication Lubrication

140-450: A wide range of molecular weights from 300   g/mol to 10,000,000   g/mol. PEG and PEO are liquids or low-melting solids, depending on their molecular weights . While PEG and PEO with different molecular weights find use in different applications and have different physical properties (e.g. viscosity ) due to chain length effects, their chemical properties are nearly identical. Different forms of PEG are also available, depending on

168-492: Is a polyether compound derived from petroleum with many applications, from industrial manufacturing to medicine . PEG is also known as polyethylene oxide ( PEO ) or polyoxyethylene ( POE ), depending on its molecular weight . The structure of PEG is commonly expressed as H−(O−CH 2 −CH 2 ) n −OH. PEO's have "very low single dose oral toxicity", on the order of tens of grams per kilogram of human body weight when ingested by mouth. Because of its low toxicity, PEO

196-412: Is coupled to hydrophobic molecules to produce non-ionic surfactants . PEG and related polymers (PEG phospholipid constructs) are often sonicated when used in biomedical applications. However, as reported by Murali et al., PEG is very sensitive to sonolytic degradation and PEG degradation products can be toxic to mammalian cells. It is, thus, imperative to assess potential PEG degradation to ensure that

224-413: Is difficult, the price for this type of quality is often 10–1000 fold that of polydisperse PEG. PEGs are also available with different geometries. The numbers that are often included in the names of PEGs indicate their average molecular weights (e.g. a PEG with n = 9 would have an average molecular weight of approximately 400 daltons , and would be labeled PEG 400 ). Most PEGs include molecules with

252-485: Is preferred in the biomedical field, whereas PEO is more prevalent in the field of polymer chemistry. Because different applications require different polymer chain lengths, PEG has tended to refer to oligomers and polymers with a molecular mass below 20,000   g/mol, PEO to polymers with a molecular mass above 20,000   g/mol, and POE to a polymer of any molecular mass. PEGs are prepared by polymerization of ethylene oxide and are commercially available over

280-401: Is produced by the interaction of ethylene oxide with water, ethylene glycol , or ethylene glycol oligomers. The reaction is catalyzed by acidic or basic catalysts. Ethylene glycol and its oligomers are preferable as a starting material instead of water because they allow the creation of polymers with a low polydispersity (narrow molecular weight distribution). Polymer chain length depends on

308-465: Is the process or technique of using a lubricant to reduce friction and wear and tear in a contact between two surfaces. The study of lubrication is a discipline in the field of tribology . Lubrication mechanisms such as fluid-lubricated systems are designed so that the applied load is partially or completely carried by hydrodynamic or hydrostatic pressure, which reduces solid body interactions (and consequently friction and wear). Depending on

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336-476: Is used in a variety of edible products. It is also used as a lubricating coating for various surfaces in aqueous and non-aqueous applications. The precursor to PEGs is ethylene oxide , which is hazardous. Ethylene glycol and its ethers are nephrotoxic ( poisonous to the kidneys ) if applied to damaged skin. The United States Food and Drug Administration (FDA or US FDA) regards PEG as biologically inert and safe. A 2015 study appears to challenge

364-481: The initiator used for the polymerization process – the most common initiator is a monofunctional methyl ether PEG, or methoxypoly(ethylene glycol), abbreviated mPEG. Lower-molecular-weight PEGs are also available as purer oligomers, referred to as monodisperse, uniform, or discrete. Very high-purity PEG has recently been shown to be crystalline, allowing the determination of a crystal structure by x-ray crystallography . Since purification and separation of pure oligomers

392-718: The 50th anniversary of the salvage. Vasa I: The Archaeology of a Swedish Warship of 1628 was published at the end of 2006. Subsequent volumes will be published annually. The museum also features four other museum ships moored in the harbour outside: the ice breaker Sankt Erik (launched 1915), the lightvessel Finngrundet (1903), the torpedo boat Spica (1966) and the rescue boat Bernhard Ingelsson (1944). 59°19′41″N 18°05′29″E  /  59.32794°N 18.09139°E  / 59.32794; 18.09139 Polyethylene glycol Polyethylene glycol ( PEG ; / ˌ p ɒ l i ˈ ɛ θ əl ˌ iː n ˈ ɡ l aɪ ˌ k ɒ l , - ˈ ɛ θ ɪ l -, - ˌ k ɔː l / )

420-459: The FDA's conclusion. In the study, a high-sensitivity ELISA assay detected anti-PEG antibodies in 72% of random blood plasma samples collected from 1990 to 1999. According to the study's authors, this result suggests that anti-PEG antibodies may be present, typically at low levels, in people who were never treated with PEGylated drugs. Due to its ubiquity in many products and the large percentage of

448-405: The actual height of Vasa when she was fully rigged. Parts of the building are covered in wooden panels painted in dark red, blue, tar black, ochre yellow and dark green. The interior is similarly decorated, with large sections of bare, unpainted concrete, including the entire ceiling. Inside the museum the ship can be seen from six levels, from her keel to the very top of the sterncastle . Around

476-404: The degree of surface separation, different lubrication regimes can be distinguished. Adequate lubrication allows smooth, continuous operation of machine elements , reduces the rate of wear, and prevents excessive stresses or seizures at bearings. When lubrication breaks down, components can rub destructively against each other, causing heat, local welding, destructive damage and failure. As

504-416: The final material does not contain undocumented contaminants that can introduce artifacts into experimental results. PEGs and methoxypolyethylene glycols are manufactured by Dow Chemical under the trade name Carbowax for industrial use, and Carbowax Sentry for food and pharmaceutical use. They vary in consistency from liquid to solid, depending on the molecular weight, as indicated by a number following

532-425: The load increases on the contacting surfaces, distinct situations can be observed with respect to the mode of lubrication, which are called lubrication regimes: Besides supporting the load the lubricant may have to perform other functions as well, for instance it may cool the contact areas and remove wear products. While carrying out these functions the lubricant is constantly replaced from the contact areas either by

560-414: The lower sections of all three masts , a new bowsprit , winter rigging , and has had certain parts that were missing or heavily damaged replaced. The replacement parts have not been treated or painted and are therefore clearly visible against the original material that has been darkened after three centuries under water. The new museum is dominated by a large copper roof with stylized masts that represent

588-487: The museum building was organized. A total of 384 architects sent in models of their ideas and the final winners were Marianne Dahlbäck and Göran Månsson with Ask ("box"). The construction of the new building began on and around the dry dock of the old naval yard with an inauguration ceremony hosted by Prince Bertil on 2 November 1987. Vasa was towed into the flooded dry dock under the new building in December 1987, and during

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616-521: The name. They are used commercially in numerous applications, including foods, cosmetics , pharmaceutics, biomedicine , dispersing agents, solvents, ointments , suppository bases, as tablet excipients , and as laxatives . Some specific groups are lauromacrogols , nonoxynols , octoxynols , and poloxamers . The production of polyethylene glycol was first reported in 1859. Both A. V. Lourenço and Charles Adolphe Wurtz independently isolated products that were polyethylene glycols. Polyethylene glycol

644-530: The population with antibodies to PEG, which indicates an allergic reaction, hypersensitive reactions to PEG are an increasing health concern. Allergy to PEG is usually discovered after a person has been diagnosed with an allergy to several seemingly unrelated products—including processed foods, cosmetics, drugs, and other substances—that contain or were manufactured with PEG. PEG , PEO , and POE refer to an oligomer or polymer of ethylene oxide . The three names are chemically synonymous, but historically PEG

672-488: The ratio of reactants. Depending on the catalyst type, the mechanism of polymerization can be cationic or anionic. The anionic mechanism is preferable because it allows one to obtain PEG with a low polydispersity . Polymerization of ethylene oxide is an exothermic process. Overheating or contaminating ethylene oxide with catalysts such as alkalis or metal oxides can lead to runaway polymerization, which can end in an explosion after

700-428: The relative movement (hydrodynamics) or by externally induced forces. Lubrication is required for correct operation of mechanical systems such as pistons , pumps , cams , bearings , turbines , gears , roller chains , cutting tools etc. where without lubrication the pressure between the surfaces in close proximity would generate enough heat for rapid surface damage which in a coarsened condition may literally weld

728-483: The ship are numerous exhibits and models portraying the construction, sinking, location, and recovery of the ship. There are also exhibits that expand on the history of Sweden in the 17th century, providing background information for why the ship was built. A movie theatre shows a film in alternating languages on the recovery of the Vasa . The museum is in the process of publishing an 8-volume archaeological report to commemorate

756-458: The summer of 1989, when visitors were allowed onto the construction site, 228,000 people visited the half-finished museum. The museum was officially opened on 15 June 1990. So far, Vasa has been seen by over 25 million people. In 2017, the museum had a total of 1,495,760 visitors. The main hall contains the ship itself, and various exhibits related to the archaeological findings of the ships and early 17th-century Sweden. Vasa has been fitted with

784-435: The surfaces together, causing seizure . In some applications, such as piston engines, the film between the piston and the cylinder wall also seals the combustion chamber, preventing combustion gases from escaping into the crankcase. If an engine required pressurised lubrication to, say, plain bearings , there would be an oil pump and an oil filter . On early engines (such as a Sabb marine diesel ), where pressurised feed

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