The UGM-73 Poseidon missile was the second US Navy nuclear-armed submarine-launched ballistic missile (SLBM) system, powered by a two-stage solid-fuel rocket . It succeeded the UGM-27 Polaris beginning in 1972, bringing major advances in warheads and accuracy. It was followed by Trident I in 1979, and Trident II in 1990.
110-508: A development study for a longer range version of the Polaris missile—achieved by enlarging it to the maximum possible size allowed by existing launch tubes—started in 1963. Tests had already shown that Polaris missiles could be operated without problems in launch tubes that had their fiberglass liners and locating rings removed. The project was given the title Polaris B3 in November, but the missile
220-484: A back brace , or in cases of radical surgery to repair an injury or other defect. A body cast that encases the trunk (with "straps" over the shoulders) is usually called a body jacket. These are often very uncomfortable. An EDF (elongation, derotation, flexion) cast is used for the treatment of Infantile Idiopathic scoliosis. This method of treatment for correction was developed by UK scoliosis specialist Min Mehta. Scoliosis
330-424: A glass with no true melting point, can be used as a glass fiber for fiberglass but has the drawback that it must be worked at very high temperatures. In order to lower the necessary work temperature, other materials are introduced as "fluxing agents" (i.e., components to lower the melting point). Ordinary A-glass ("A" for "alkali-lime") or soda lime glass, crushed and ready to be remelted, as so-called cullet glass,
440-539: A 5 mg/m total limit. As of 2001, the Hazardous Substances Ordinance in Germany dictates a maximum occupational exposure limit of 86 mg/m . In certain concentrations, a potentially explosive mixture may occur. Further manufacture of GRP components (grinding, cutting, sawing) creates fine dust and chips containing glass filaments, as well as tacky dust, in quantities high enough to affect health and
550-602: A November, 2011 modification to its Proposition 65 listing to include only "Glass wool fibers (inhalable and biopersistent)." Therefore a cancer warning label for biosoluble fiber glass home and building insulation is no longer required under federal or California law. As of 2012, the North American Insulation Manufacturers Association stated that fiberglass is safe to manufacture, install and use when recommended work practices are followed to reduce temporary mechanical irritation. As of 2012,
660-439: A binder. It is typically processed using the hand lay-up technique, where sheets of material are placed on a mold and brushed with resin. Because the binder dissolves in resin, the material easily conforms to different shapes when wetted out. After the resin cures, the hardened product can be taken from the mold and finished. Using chopped strand mat gives the fiberglass isotropic in-plane material properties. A coating or primer
770-414: A broken bone (or bones), in place until healing is confirmed. It is similar in function to a splint . Plaster bandages consist of a cotton bandage that has been combined with plaster of paris , which hardens after it has been made wet. Plaster of Paris is calcined gypsum (roasted gypsum), ground to a fine powder by milling. When water is added, the more soluble form of calcium sulfate returns to
880-401: A cast may be called a cylinder cast. Where the wrist or ankle is included, it may be called a long arm or long leg cast. Body casts, which cover the trunk of the body, and in some cases the neck up to or including the head (see Minerva Cast, below) or one or more limbs, are used less frequently today, and are most commonly used in the cases of small children, who cannot be trusted to comply with
990-417: A chemical solution. The individual filaments are now bundled in large numbers to provide a roving . The diameter of the filaments, and the number of filaments in the roving, determine its weight , typically expressed in one of two measurement systems: These rovings are then either used directly in a composite application such as pultrusion , filament winding (pipe), gun roving (where an automated gun chops
1100-401: A combined stream from a chopper gun. Workers roll out the spray-up to compact the laminate. Wood, foam or other core material may then be added, and a secondary spray-up layer imbeds the core between the laminates. The part is then cured, cooled, and removed from the reusable mold. Pultrusion is a manufacturing method used to make strong, lightweight composite materials. In pultrusion, material
1210-456: A kitchen counter top and their head held over the kitchen sink. The Minerva cast and the Risser cast are used to protect an injured spine or as part of the treatment for a spinal deformity (see scoliosis ), but are seen less frequently today. The Minerva cast includes the trunk of the body (sometimes extending down only so far as the rib cage) as well as the patient's head, with openings provided for
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#17328700825111320-430: A liner to prevent gas leakage or as a barrier to protect the composite from the fluid to be stored. Filament winding is well suited to automation, and there are many applications, such as pipe and small pressure vessels that are wound and cured without any human intervention. The controlled variables for winding are fiber type, resin content, wind angle, tow or bandwidth and thickness of the fiber bundle. The angle at which
1430-551: A method of treating fractures that he had observed in Turkey. He noted that gypsum plaster (plaster of Paris) was moulded around the patient's leg to cause immobilization. If the cast became loose due to atrophy or a reduction in swelling, then additional gypsum plaster was added to fill the space. Adapting the use of plaster of Paris for use in hospitals, however, took some time. In 1828, doctors in Berlin were treating leg fractures by aligning
1540-913: A post-exposure recovery period." Historic reviews of the epidemiology studies had been conducted by Harvard's Medical and Public Health Schools in 1995, the National Academy of Sciences in 2000, the Agency for Toxic Substances and Disease Registry ("ATSDR") in 2004, and the National Toxicology Program in 2011. which reached the same conclusion as IARC that there is no evidence of increased risk from occupational exposure to glass wool fibers. Genetic and toxic effects are exerted through production of reactive oxygen species , which can damage DNA, and cause chromosomal aberrations , nuclear abnormalities, mutations, gene amplification in proto-oncogenes , and cell transformation in mammalian cells. There
1650-473: A professor of Surgery. In 1840, he became the professor of surgery at the academy of military medicine in St. Petersburg. Pirogov introduced the use of ether anaesthesia to Russia and made important contributions to the study of cross-sectional human anatomy. With the help of his patron, the grand duchess Helene Pavlovna , he introduced female nurses into the military hospitals at the same time that Florence Nightingale
1760-424: A rocket motor when the missile was still in the submarine was considered very dangerous. Therefore, the missile was ejected from its launch tube using high pressure steam produced by a solid-fueled boiler. The main rocket motor ignited automatically when the missile had risen approximately 10 metres (33 ft) above the submarine. The first test launch took place on 16 August 1968, the first successful at-sea launch
1870-459: A sheet called a chopped strand mat, or woven into glass cloth . The plastic matrix may be a thermoset polymer matrix —most often based on thermosetting polymers such as epoxy , polyester resin , or vinyl ester resin —or a thermoplastic . Cheaper and more flexible than carbon fiber , it is stronger than many metals by weight, non- magnetic , non- conductive , transparent to electromagnetic radiation , can be molded into complex shapes, and
1980-407: A snug and therefore more comfortable fit. In addition, plaster is much smoother and does not snag clothing or abrade the skin. Upper extremity casts encase the arm, wrist, or hand. A long arm cast encases the arm from the hand to about 5 cm below the armpit, leaving fingers and thumbs free. A short arm cast, in contrast, stops just below the elbow. Both varieties may, depending on the injury and
2090-415: A thermoplastic inner tank which acts as a preform during construction. Much more reliable tanks are made using woven mat or filament wound fiber, with the fiber orientation at right angles to the hoop stress imposed in the sidewall by the contents. Such tanks tend to be used for chemical storage because the plastic liner (often polypropylene ) is resistant to a wide range of corrosive chemicals. Fiberglass
2200-401: A waterproof, washable, lightweight, strong and comfortable way of recovering from fractures . Casts are typically removed by perforation using a cast saw, an oscillating saw designed to cut rigid material such as plaster or fiberglass while not harming soft tissue. Manually operated shears, patented in 1950 by Neil McKay , may be used on pediatric or other patients who may be affected by
2310-555: A wet sponge or brush as they were applied and rubbed by hand until they hardened. Plaster of Paris dressings were first employed in the treatment of mass casualties in the 1850s during the Crimean War by Nikolai Ivanovich Pirogov (1810–1881). Pirogov was born in Moscow and received his early education there. After obtaining a medical degree at Dorpat (now Tartu, Estonia ) he studied at Berlin and Göttingen before returning to Dorpat as
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#17328700825112420-409: Is a 3-dimensional problem that requires correction in all three planes. The EDF casting method can elongate the spine through traction, derotate the spine/pelvis, and improve lordosis and overall body shape and alignment. EDF differs from Risser casting. EDF casts are either over or under the shoulder, and have a large mushroom opening on the front to allow for proper chest expansion. On the back, there
2530-555: Is a double hip spica. A one-and-a-half hip spica encases one leg to the ankle or foot and the other to just above the knee. The extent to which the hip spica covers the trunk depends greatly on the injury and the surgeon; the spica may extend only to the navel, allowing mobility of the spine and the possibility of walking with the aid of crutches, or may extend to the rib cage or even to the armpits in some rare cases. Hip spicas are common in maintaining reduction of femoral fractures and are also used for congenital hip dislocations, mostly while
2640-427: Is a fabrication technique mainly used for manufacturing open (cylinders) or closed-end structures (pressure vessels or tanks). The process involves winding filaments under tension over a male mandrel. The mandrel rotates while a wind eye on a carriage moves horizontally, laying down fibers in the desired pattern. The most common filaments are carbon or glass fiber and are coated with synthetic resin as they are wound. Once
2750-408: Is a small cutout on the concavity of the curve, not going past the midline. It was found that the spine became more aligned with this cutout than without, and that it helped correct rotation. A cast that includes the trunk of the body and one or more limbs is a spica cast, just as is a cast that includes the "trunk" of the arm and one or more fingers or the thumb. For example, a shoulder spica includes
2860-422: Is a true rarity in recorded medical history, and this type of large scale cast appears more commonly in various Hollywood movies and on television shows. The term body cast (or full body cast) is sometimes casually used by laymen to describe any of a number of body or spica casts, from a simple body jacket to a more extensive hip spica. Due to the nature of the dressing, the limb is unreachable during treatment, and
2970-446: Is also available. There are some washable casts like FlexiOH which provide good ventilation and maintain good skin hygiene. With this cast, patients are able to bathe and go out in the rain. These types of casts have advantages that deliver patients a better treatment than conventional casts made of plaster of Paris or Fiberglass. They are the next generation of orthopedic immobilization photo-curing specialty-resin technology that enables
3080-545: Is also indirect, inflammation-driven genotoxicity through reactive oxygen species by inflammatory cells . The longer and thinner as well as the more durable (biopersistent) fibers were, the more potent they were in damage. In the US, fine mineral fiber emissions have been regulated by the EPA , but respirable fibers (“particulates not otherwise regulated”) are regulated by Occupational Safety and Health Administration (OSHA); OSHA has set
3190-432: Is also used for septic tanks . Glass-reinforced plastics are also used to produce house building components such as roofing laminate, door surrounds, over-door canopies, window canopies and dormers, chimneys, coping systems, and heads with keystones and sills. The material's reduced weight and easier handling, compared to wood or metal, allows faster installation. Mass-produced fiberglass brick-effect panels can be used in
3300-401: Is applied to the chosen mold to allow the finished product to be cleanly removed from the mold. Resin—typically a 2-part thermoset polyester, vinyl, or epoxy—is mixed with its hardener and applied to the surface. Sheets of fiberglass matting are laid into the mold, then more resin mixture is added using a brush or roller. The material must conform to the mold, and air must not be trapped between
3410-479: Is applied to the roving to help protect the glass filaments for processing and manipulation and to ensure proper bonding to the resin matrix, thus allowing for the transfer of shear loads from the glass fibers to the thermoset plastic. Without this bonding, the fibers can 'slip' in the matrix causing localized failure. An individual structural glass fiber is both stiff and strong in tension and compression —that is, along its axis. Although it might be assumed that
UGM-73 Poseidon - Misplaced Pages Continue
3520-483: Is called pultrusion . The manufacturing process for glass fibers suitable for reinforcement uses large furnaces to gradually melt the silica sand, limestone , kaolin clay , fluorspar , colemanite , dolomite and other minerals until a liquid forms. It is then extruded through bushings ( spinneret ), which are bundles of very small orifices (typically 5–25 micrometres in diameter for E-Glass, 9 micrometres for S-Glass). These filaments are then sized (coated) with
3630-478: Is chemically inert under many circumstances. Applications include aircraft, boats, automobiles, bath tubs and enclosures, swimming pools , hot tubs , septic tanks , water tanks , roofing, pipes, cladding, orthopedic casts , surfboards , and external door skins. Other common names for fiberglass are glass-reinforced plastic ( GRP ), glass-fiber reinforced plastic ( GFRP ) or GFK (from German : Glasfaserverstärkter Kunststoff ). Because glass fiber itself
3740-579: Is credited with producing the first composite boat in 1937 but did not proceed further at the time because of the brittle nature of the plastic used. In 1939 Russia was reported to have constructed a passenger boat of plastic materials, and the United States a fuselage and wings of an aircraft. The first car to have a fiberglass body was a 1946 prototype of the Stout Scarab , but the model did not enter production. Unlike glass fibers used for insulation, for
3850-401: Is essentially an entire two-dimensional plane; with woven fabrics or unidirectional layers, directionality of stiffness and strength can be more precisely controlled within the plane. A fiberglass component is typically of a thin "shell" construction, sometimes filled on the inside with structural foam, as in the case of surfboards. The component may be of nearly arbitrary shape, limited only by
3960-513: Is pulled through forming machinery using either a hand-over-hand method or a continuous-roller method (as opposed to extrusion , where the material is pushed through dies). In fiberglass pultrusion, fibers (the glass material) are pulled from spools through a device that coats them with a resin. They are then typically heat-treated and cut to length. Fiberglass produced this way can be made in a variety of shapes and cross-sections, such as W or S cross-sections. People can be exposed to fiberglass in
4070-639: Is required, such as equipment cabinets and steel support structures, due to the ease with which it can be molded and painted to blend with existing structures and surfaces. Other uses include sheet-form electrical insulators and structural components commonly found in power-industry products. Because of fiberglass's lightweight and durability, it is often used in protective equipment such as helmets. Many sports use fiberglass protective gear, such as goaltenders' and catchers' masks. Storage tanks can be made of fiberglass with capacities up to about 300 tonnes . Smaller tanks can be made with chopped strand mat cast over
4180-505: Is sometimes referred to as "fiberglass", the composite is also called fiberglass-reinforced plastic ( FRP ). This article uses "fiberglass" to refer to the complete fiber-reinforced composite material, rather than only to the glass fiber within it. Glass fibers have been produced for centuries, but the earliest patent was awarded to the Prussian inventor Hermann Hammesfahr (1845–1914) in the U.S. in 1880. Mass production of glass strands
4290-430: Is still popular). Pirogov went on to develop his own methods, although he was aware of Mathijsen's work. Pirogov's method involved soaking coarse cloth in a plaster of Paris mixture immediately before application to the limbs, which were protected either by stockings or cotton pads. Large dressings were reinforced with pieces of wood. As time passed and the method moved more into the mainstream some disagreement arose as to
4400-402: Is that the resins used are subject to contraction during the curing process. For polyester this contraction is often 5–6%; for epoxy, about 2%. Because the fibers do not contract, this differential can create changes in the shape of the part during curing. Distortions can appear hours, days, or weeks after the resin has set. While this distortion can be minimized by symmetric use of the fibers in
4510-460: Is used when tensile strength (high modulus) is important and is thus an important building and aircraft epoxy composite (it is called R-glass, "R" for "reinforcement" in Europe). C-glass ("C" for "chemical resistance") and T-glass ("T" is for "thermal insulator"—a North American variant of C-glass) are resistant to chemical attack; both are often found in insulation-grades of blown fiberglass. Fiberglass
UGM-73 Poseidon - Misplaced Pages Continue
4620-433: Is versatile because it is lightweight, strong, weather-resistant, and can have a variety of surface textures. During World War II, fiberglass was developed as a replacement for the molded plywood used in aircraft radomes (fiberglass being transparent to microwaves ). Its first main civilian application was for the building of boats and sports car bodies, where it gained acceptance in the 1950s. Its use has broadened to
4730-564: The International Agency for Research on Cancer (IARC) as "not classifiable as to carcinogenicity to humans" ( IARC group 3 ). "Epidemiologic studies published during the 15 years since the previous IARC monographs review of these fibers in 1988 provide no evidence of increased risks of lung cancer or mesothelioma (cancer of the lining of the body cavities) from occupational exposures during the manufacture of these materials, and inadequate evidence overall of any cancer risk." In June 2011,
4840-554: The Soviet Union had collapsed, 12 Ohio-class submarines had been commissioned, and the START I treaty had gone into effect, so the 31 older Poseidon- and Trident I-armed SSBNs were disarmed, withdrawing Poseidon from service. Fiberglass Fiberglass ( American English ) or fibreglass ( Commonwealth English ) is a common type of fiber-reinforced plastic using glass fiber . The fibers may be randomly arranged, flattened into
4950-471: The hair follicles and sweat glands can lead to severe and painful dermatitis . Other limitations of plaster casts include their weight, which can be quite considerable, thus restricting movement, especially of a child. Removal of the cast requires destroying the cast itself. The process is often noisy, making use of a special oscillating saw that can easily cut the hard cast material but has difficulty cutting soft material like cast padding or skin. Although
5060-425: The metatarsals in both weight bearing and non-weight bearing leg casts. These are referred to as toeplates in the orthopedic discipline of medicine. This addition may be applied to further support and stabilize the metatarsals by limiting motion through a higher degree of immobilization, as well as protecting the toes from additional blunt force trauma. Typically leg casts with toeplates are prescribed for injuries to
5170-556: The 1970s as an upgrade to its Polaris A3T boats, and like the US this would have kept the existing hulls. Although the Navy's favoured option, the British government instead adopted Chevaline , a two warhead MRV system with decoys, on the existing Polaris airframes and later moved to the Trident D5 in new boats. Beginning in 1979, 12 Poseidon-equipped SSBNs were refitted with Trident I . By 1992,
5280-539: The European Union and Germany have classified synthetic glass fibers as possibly or probably carcinogenic, but fibers can be exempt from this classification if they pass specific tests. A 2012 health hazard review for the European Commission stated that inhalation of fiberglass at concentrations of 3, 16 and 30 mg/m3 "did not induce fibrosis nor tumours except transient lung inflammation that disappeared after
5390-550: The Middle East. As a result, Larrey accumulated a vast experience of military medicine and surgery. One of his patients after the Battle of Borodino in 1812 was an infantry officer whose arm was amputated at the shoulder. The patient was evacuated immediately following the operation and passed from Russia, through Poland and Germany. When the dressing was removed on his arrival home in France,
5500-553: The US National Toxicology Program (NTP) removed from its Report on Carcinogens all biosoluble glass wool used in home and building insulation and for non-insulation products. However, NTP still considers fibrous glass dust to be "reasonably anticipated [as] a human carcinogen (Certain Glass Wool Fibers (Inhalable))". Similarly, California's Office of Environmental Health Hazard Assessment (OEHHA) published
5610-428: The above common forms, body casts could come in nearly any size and configuration. For example, from the 1910s to the 1970s, use of a turnbuckle cast, which used metal turnbuckles to twist two halves of the cast so as to forcibly straighten the spine before surgery was common. The turnbuckle cast had no single configuration, and could be as small as a body jacket split in half, or could include the head, one or both legs to
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#17328700825115720-458: The air near manufacturing facilities or when they are near building fires or implosions . The American Lung Association advises that fiberglass insulation should never be left exposed in an occupied area. Since work practices are not always followed, and fiberglass is often left exposed in basements that later become occupied, people can get exposed. No readily usable biological or clinical indices of exposure exist. Fiberglass will irritate
5830-548: The application time of the cast and increases the cost of the cast. Drying time, however, can be inconvenient enough to warrant a cast and bandage moisture protector. These waterproof covers allow for bathing and showering while wearing either a plaster or fiberglass cast. The waterproof cast cover stays tightly around the cast and prevents water from ever reaching it while the patient is in contact with water. The cover can easily be removed to dry, and can be re-used often. Cast liners are often cotton, though waterproof lining material
5940-599: The automotive and sport equipment sectors. In the production of some products, such as aircraft, carbon fiber is now used instead of fiberglass, which is stronger by volume and weight. Advanced manufacturing techniques such as pre-pregs and fiber rovings extend fiberglass's applications and the tensile strength possible with fiber-reinforced plastics. Fiberglass is also used in the telecommunications industry for shrouding antennas , due to its RF permeability and low signal attenuation properties. It may also be used to conceal other equipment where no signal permeability
6050-412: The bones in a long narrow box, which they filled with moist sand. Substitution of plaster of Paris for the sand was the next logical step. Such plaster casts did not succeed however as the patient was confined to bed due to the casts being heavy and cumbersome. Plaster of Paris bandages were introduced in different forms by two army surgeons, one at a peacetime home station and another on active service at
6160-405: The cast clean and dry. Because the hips cannot bend, using a toilet is difficult, if not impossible. It is therefore necessary for the patient to either use a diaper, bedpan, or catheters to manage bodily waste eliminations. Bathing must be done by sponge baths. Hair may be shampooed by using plastic wash basins under the head. To shampoo wash the hair of a child, the child can be lifted and placed on
6270-467: The casted patient to not lift them by this spreader bar, as it may break and this could cause injury to the patient. To facilitate toileting or diaper changing and hygienic cleaning, an opening is created in the cast at the groin. The opening is normally referred to as the "perineal opening". It is formed either during cast application or after cast application by cutting the hole with the cast saw. The opening must then be petalled or lined to keep this area of
6380-417: The child is still an infant. In some cases, a hip spica may only extend down one or more legs to above the knee. Such casts, called pantaloon casts, are occasionally seen to immobilize an injured lumbar spine or pelvis, in which case the trunk portion of the cast usually extends to the armpits. Mobility is severely restricted by the hip spica cast and walking without crutches or a walker is impossible because
6490-550: The complexity and tolerances of the mold used for manufacturing the shell. The mechanical functionality of materials is heavily reliant on the combined performances of both the resin (AKA matrix) and fibers. For example, in severe temperature conditions (over 180 °C), the resin component of the composite may lose its functionality, partially due to bond deterioration of resin and fiber. However, GFRPs can still show significant residual strength after experiencing high temperatures (200 °C). One notable feature of fiberglass
6600-412: The construction of composite housing, and can include insulation to reduce heat loss. In rod pumping applications, fiberglass rods are often used for their high tensile strength to weight ratio. Fiberglass rods provide an advantage over steel rods because they stretch more elastically (lower Young's modulus ) than steel for a given weight, meaning more oil can be lifted from the hydrocarbon reservoir to
6710-973: The design, a certain amount of internal stress is created; and if it becomes too great, cracks form. The most common types of glass fiber used in fiberglass is E-glass , which is alumino-borosilicate glass with less than 1% w/w alkali oxides, mainly used for glass-reinforced plastics. Other types of glass used are A-glass ( A lkali-lime glass with little or no boron oxide), E-CR-glass ( E lectrical/ C hemical R esistance; alumino-lime silicate with less than 1% w/w alkali oxides, with high acid resistance), C-glass (alkali-lime glass with high boron oxide content, used for glass staple fibers and insulation), D-glass (borosilicate glass, named for its low D ielectric constant), R-glass (alumino silicate glass without MgO and CaO with high mechanical requirements as R einforcement), and S-glass (alumino silicate glass without CaO but with high MgO content with high tensile strength). Pure silica (silicon dioxide), when cooled as fused quartz into
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#17328700825116820-470: The doctor's decision, include one or more fingers or the thumb, in which case it is called a finger spica or thumb spica cast. Lower extremity casts are classified similarly, with a cast encasing both the foot and the leg to the hip being called a long leg cast, while a cast encasing the patient's foot, ankle and lower leg ending below the knee being called a short leg cast. A walking heel may be applied for ambulation. These heels, when properly applied, elevate
6930-433: The early 1940s, and many sailing vessels made after 1950 were built using the fiberglass lay-up process . As of 2022, boats continue to be made with fiberglass, though more advanced techniques such as vacuum bag moulding are used in the construction process. Though most bullet-resistant armours are made using different textiles, fiberglass composites have been shown to be effective as ballistic armor. Filament winding
7040-455: The early mobilization of patients with fractures and a marked reduction in hospital time required. Although these bandages were an improvement over Larrey's method, they were far from ideal. They required a long time to apply and dry and there was often shrinkage and distortion. A great deal of interest had been aroused in Europe around 1800 by a British diplomat, consul William Eton , who described
7150-562: The eyes, skin, and the respiratory system. Hence, symptoms can include itchy eyes, skin, nose, sore throat, hoarseness, dyspnea (breathing difficulty) and cough. Peak alveolar deposition was observed in rodents and humans for fibers with diameters of 1 to 2 μm. In animal experiments, adverse lung effects such as lung inflammation and lung fibrosis have occurred, and increased incidences of mesothelioma , pleural sarcoma , and lung carcinoma had been found with intrapleural or intratracheal instillations in rats. As of 2001, in humans only
7260-563: The fiber has an effect on the properties of the final product. A high angle "hoop" will provide circumferential or "burst" strength, while lower angle patterns (polar or helical) will provide greater longitudinal tensile strength. Products currently being produced using this technique range from pipes, golf clubs, Reverse Osmosis Membrane Housings, oars, bicycle forks, bicycle rims, power and transmission poles, pressure vessels to missile casings, aircraft fuselages and lamp posts and yacht masts. A release agent, usually in either wax or liquid form,
7370-434: The fiber is weak in compression, it is actually only the long aspect ratio of the fiber which makes it seem so; i.e., because a typical fiber is long and narrow, it buckles easily. On the other hand, the glass fiber is weak in shear—that is, across its axis. Therefore, if a collection of fibers can be arranged permanently in a preferred direction within a material, and if they can be prevented from buckling in compression,
7480-415: The fiberglass and the mold. Additional resin is applied and possibly additional sheets of fiberglass. Hand pressure, vacuum or rollers are used to be sure the resin saturates and fully wets all layers, and that any air pockets are removed. The work must be done quickly before the resin starts to cure unless high-temperature resins are used which will not cure until the part is warmed in an oven. In some cases,
7590-455: The field of Waterloo . At the time of the development of his bandage he was chief surgeon in the Belgium army. Seutin's "bandage amidonnee" consisted of cardboard splints and bandages soaked in a solution of starch and applied wet. These dressings required 2 to 3 days to dry, depending on the temperature and humidity of the surroundings. The substitution of Dextrin for starch, advocated by Velpeau,
7700-420: The final structure to be strong, the fiber's surfaces must be almost entirely free of defects, as this permits the fibers to reach gigapascal tensile strengths . If a bulk piece of glass were defect-free, it would be as strong as glass fibers; however, it is generally impractical to produce and maintain bulk material in a defect-free state outside of laboratory conditions. The process of manufacturing fiberglass
7810-422: The floor. Some children even learn to walk by holding themselves up against furniture. A child in a spica cast must always be supervised and safety must always be considered when they are at a mobile phase of their healing to prevent reinjury or damage to the cast. Many spica casts have a spreader bar between the legs to help strengthen the cast and support the legs in the proper positions. It is important when moving
7920-408: The foot and metatarsals. Ordinarily, a leg cast applied for the treatment of a stable ankle fracture would not use the toeplate design because there is no need to immobilize and limit the motion of the patient's toes. In some cases, a cast may include the upper and lower arm and the elbow, but leave the wrist and hand free, or the upper and lower leg and the knee, leaving the foot and ankle free. Such
8030-648: The front. Antonius Mathijsen (1805–1878) was born in Budel , the Netherlands, where his father was the village doctor. He was educated in Brussels, Maastricht and Utrecht obtaining the degree of doctor of medicine at Gissen in 1837. He spent his entire career as a medical officer in the Dutch Army. While he was stationed at Haarlem in 1851, he developed a method of applying plaster of Paris bandages. A brief note describing his method
8140-408: The functionality of machines and equipment. The installation of effective extraction and filtration equipment is required to ensure safety and efficiency. Orthopedic cast An orthopedic cast , or simply cast , is a shell, frequently made from plaster or fiberglass , that encases a limb (or, in some cases, large portions of the body) to stabilize and hold anatomical structures—most often
8250-459: The gas content of the material was replaced by plastic. This reduced the insulation properties to values typical of the plastic, but now for the first time, the composite showed great strength and promise as a structural and building material. Many glass fiber composites continued to be called "fiberglass" (as a generic name) and the name was also used for the low-density glass wool product containing gas instead of plastic. Ray Greene of Owens Corning
8360-473: The glass into short lengths and drops it into a jet of resin, projected onto the surface of a mold), or in an intermediary step, to manufacture fabrics such as chopped strand mat (CSM) (made of randomly oriented small cut lengths of fiber all bonded together), woven fabrics, knit fabrics or unidirectional fabrics. Chopped strand mat (CSM) is a form of reinforcement used in fiberglass. It consists of glass fibers laid randomly across each other and held together by
8470-411: The hips cannot bend. There is a serious danger of falling if the patient in a hip spica cast tries to get upright to walk without assistance because they lack the ability to control their balance. Patients normally remain in a bed or rely on a reclining wheelchair or children's stroller. Children in spica casts can sometimes learn to get mobile by scooting around on skateboards, or pulling themselves across
8580-400: The knees or feet, or one arm to the elbow or wrist. Despite the large size and extreme immobilization some casts, particularly those used in or before the 1970s, the popular term full body cast is something of a misnomer. The popular and media-driven conception of a massive cast encasing all four limbs, the trunk, and the head – sometimes leaving only small slits for the eyes, nose, and mouth –
8690-441: The legal limit ( permissible exposure limit ) for fiberglass exposure in the workplace as 15 mg/m total and 5 mg/m in respiratory exposure over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 3 fibers/cm (less than 3.5 micrometers in diameter and greater than 10 micrometers in length) as a time-weighted average over an 8-hour workday, and
8800-491: The man widely regarded as the leading French surgeon at the beginning of the 19th century, reduced the drying time to 6 hours. Although this was a vast improvement, it was still a long time, especially in the harsh environment of the battlefield. A good description of Seutin's technique was provided by Sampson Gamgee who learned it from Seutin in France during the winter of 1851–52 and went on to promote its use in Britain. The limb
8910-413: The mandrel is completely covered to the desired thickness, the resin is cured; often the mandrel is placed in an oven to achieve this, though sometimes radiant heaters are used with the mandrel still turning in the machine. Once the resin has cured, the mandrel is removed, leaving the hollow final product. For some products such as gas bottles, the 'mandrel' is a permanent part of the finished product forming
9020-449: The material will be preferentially strong in that direction. Furthermore, by laying multiple layers of fiber on top of one another, with each layer oriented in various preferred directions, the material's overall stiffness and strength can be efficiently controlled. In fiberglass, it is the plastic matrix which permanently constrains the structural glass fibers to directions chosen by the designer. With chopped strand mat, this directionality
9130-586: The more biopersistent materials like ceramic fibres, which are used industrially as insulation in high-temperature environments such as blast furnaces , and certain special-purpose glass wools not used as insulating materials remain classified as possible carcinogens ( IARC Group 2B ). The more commonly used glass fibre wools including insulation glass wool , rock wool and slag wool are considered not classifiable as to carcinogenicity to humans ( IARC Group 3 ). In October 2001, all fiberglass wools commonly used for thermal and acoustical insulation were reclassified by
9240-420: The noise of the saw. The earliest methods of holding a reduced fracture involved using splints . These are rigid strips laid parallel to each other alongside the bone. The Ancient Egyptians used wooden splints made of bark wrapped in linen. They also used stiff bandages for support that were probably derived from embalming techniques. The use of plaster of Paris to cover walls is evident, but it seems it
9350-412: The patient's casted foot while helping to maintain better hygiene by preventing the cast from directly contacting potentially dirty or wet ground surfaces. Where the patient is not to walk on the injured limb, crutches or a wheelchair may be provided. The foot's under-sole portion of a leg cast may be extended terminating at the tip of the patient's toes, to create a rigid support that limits motion of
9460-429: The patient's face, ears, and sometimes the top of the head and hair. The Risser cast was similar, extending from the patient's hips to the neck and sometimes including part of the head. Both of these casts could, with care and the doctor's permission, be walked in during convalescence. However, in some cases the Risser cast would extend into one or more pantaloons, in which case mobility was far more restricted. Aside from
9570-450: The problems associated with cutting off air to skin contact, and also some improvements were made. Eventually Pirogov's method gave way to Mathijsen's. Among the improvements suggested as early as 1860 was that of making the dressing resistant to water by painting the dried plaster of Paris with a mixture of shellac dissolved in alcohol. The first commercial bandages were not produced until 1931 in Germany, and were called Cellona. Before that
9680-481: The relatively insoluble form, and heat is produced. The setting of unmodified plaster starts about 10 minutes after mixing and is complete in about 45 minutes; however, the cast is not fully dry for 72 hours. Bandages of synthetic materials are also used—often knitted fiberglass bandages impregnated with polyurethane , sometimes bandages of thermoplastic . These are lighter and dry much faster than plaster bandages. However, plaster can be more easily moulded to make
9790-401: The removal is often painless, this can be distressing for the patient, especially children. A cast saw can cut, abrade, or burn skin, but those results are uncommon. Additionally, plaster of Paris casts break down if patients get them wet. Due to the limitations of plaster of Paris, surgeons have also experimented with other types of materials for use as splints. An early plastic like material
9900-423: The skin under the plaster becomes dry and scaly because the discarded outer skin cells are not washed or brushed off. Also, plaster of Paris casts can result in cutaneous complications including macerations, ulcerations, infections, rashes, itching, burns, and allergic contact dermatitis, which may also be due to the presence of formaldehyde within the plaster bandages. In hot weather, staphylococcal infection of
10010-581: The standard method for the healing of fractures was bed rest and restriction of activity. The search for a simpler, less-time-consuming, method led to the development of the first modern occlusive dressings, stiffened at first with starch and later with plaster-of-paris. The ambulatory treatment of fractures was the direct result of these innovations. The innovation of the modern cast can be traced to, among others, four military surgeons, Dominique Jean Larrey , Louis Seutin , Antonius Mathijsen , and Nikolai Ivanovich Pirogov . Dominique Jean Larrey (1768–1842)
10120-628: The surface with each stroke, all while reducing the load on the pumping unit. Fiberglass rods must be kept in tension, however, as they frequently part if placed in even a small amount of compression. The buoyancy of the rods within a fluid amplifies this tendency. GRP and GRE pipe can be used in a variety of above- and below-ground systems, including those for desalination, water treatment, water distribution networks, chemical process plants, water used for firefighting, hot and cold drinking water, wastewater/sewage, municipal waste and liquified petroleum gas . Fiberglass composite boats have been made since
10230-425: The toes and offer the wearer the advantage of keeping the toes out of the dirt and moisture of the street. The walking heel provides a small contact patch for the cast and creates a fluid rocking motion during the stride as the cast can pivot easily in any direction. Similarly, a weight-bearing cast shoe (cast boot, cast sandal) can help the patient walk during convalescence. Additionally, a castshoe can simply protect
10340-437: The trunk of the body and one arm, usually to the wrist or hand. Shoulder spicas are almost never seen today, having been replaced with specialized splints and slings that provide early mobility of the injury to avoid joint stiffness after healing. A hip spica includes the trunk of the body and one or more legs. A hip spica that covers only one leg to the ankle or foot is called a single hip spica, while one that covers both legs
10450-462: The twelfth century recommended bandages hardened with a flour and egg mixture as did medieval European bonesetters, who used casts made of egg white, flour, and animal fat. By the sixteenth century the famous French surgeon Ambroise Paré (1517–1590), who championed more humane treatments in medicine and promoted the use of artificial limbs, made casts of wax, cardboard, cloth, and parchment that hardened as they dried. These methods all had merit, but
10560-482: The work is covered with plastic sheets and vacuum is drawn on the work to remove air bubbles and press the fiberglass to the shape of the mold. The fiberglass spray lay-up process is similar to the hand lay-up process but differs in the application of the fiber and resin to the mold. Spray-up is an open-molding composites fabrication process where resin and reinforcements are sprayed onto a mold. The resin and glass may be applied separately or simultaneously "chopped" in
10670-415: The workplace during its fabrication, installation or removal, by breathing it in, by skin contact, or by eye contact. Furthermore, in the manufacturing process of fiberglass, styrene vapors are released while the resins are cured. These are also irritating to mucous membranes and respiratory tract. The general population can get exposed to fibreglass from insulation and building materials or from fibers in
10780-403: The wound had healed. Larrey concluded that the fact that the wound had been undisturbed had facilitated healing. After the war, Larrey began stiffening bandages using camphorated alcohol, lead acetate and egg whites beaten in water. An improved method was introduced by Louis Seutin , (1793–1865) of Brussels. In 1815 Seutin had served in the allied armies in the war against Napoleon and was on
10890-490: Was accidentally discovered in 1932 when Games Slayter , a researcher at Owens-Illinois , directed a jet of compressed air at a stream of molten glass and produced fibers. A patent for this method of producing glass wool was first applied for in 1933. Owens joined with the Corning company in 1935 and the method was adapted by Owens Corning to produce its patented "Fiberglas" (spelled with one "s") in 1936. Originally, Fiberglas
11000-450: Was gutta-percha obtained from the latex of trees found in Malaya . It resembled rubber, but contained more resins. When dry it was hard and inelastic, but when warmed it became soft and malleable. In 1851 Utterhoeven described the use of splints made from this material for the treatment of fractures. In the 1970s, the development of fibreglass casting tape made it possible to produce a cast that
11110-425: Was a glass wool with fibers entrapping a great deal of gas, making it useful as an insulator, especially at high temperatures. A suitable resin for combining the fiberglass with a plastic to produce a composite material was developed in 1936 by DuPont . The first ancestor of modern polyester resins is Cyanamid 's resin of 1942. Peroxide curing systems were used by then. With the combination of fiberglass and resin
11220-465: Was beginning a similar program in British military hospitals. Seutin had travelled through Russia demonstrating his 'starched bandage', and his technique had been adopted by both the Russian army and navy by 1837. Pirogov had observed the use of plaster of Paris bandages in the studio of a sculptor who used strips of linen soaked in liquid plaster of Paris for making models (this technique, called " modroc ,"
11330-647: Was born in a small town in southern France. He first studied medicine with his uncle, a surgeon in Toulouse. After a short tour of duty as a naval surgeon, he returned to Paris, where he became caught up in the turmoil of the French Revolution , being present at the Storming of the Bastille . From then on, he made his career as a surgeon in France's revolutionary and Napoleonic armies , which he accompanied throughout Europe and
11440-666: Was eventually named Poseidon C3 to emphasize the technical advances over its predecessor. The C3 was the only version of the missile produced, and it was also given the designation UGM-73A. Slightly longer and considerably wider and heavier than Polaris A3, Poseidon had the same 4,600 kilometres (2,500 nmi) range, greater payload capacity, improved accuracy, and multiple independently targetable reentry vehicle (MIRV) capability. MIRV capacity has been given as up to either ten or fourteen W68 thermonuclear warheads contained in Mark 3 reentry vehicles to multiple targets. As with Polaris, starting
11550-697: Was from a surface ship, the USNS ; Observation Island (from July 1 to December 16, 1969), earning the ship the Meritorious Unit Commendation , and the first test launch from a submarine took place on the USS ; James Madison on 3 August 1970. The weapon officially entered service on 31 March 1971. It eventually equipped 31 Lafayette -, James Madison -, and Benjamin Franklin -class submarines. The Royal Navy also considered adopting Poseidon in
11660-439: Was initially wrapped in wool, especially over any bony prominences. Pasteboard was then cut into shape to provide a splint, and dampened so it could be molded to the limb. The limb was then wrapped in bandages before a starch coating was applied to the outer surface. Seutin's technique for the application of the starch apparatus formed the basis of the technique used with plaster of Paris dressings today. The use of this method led to
11770-443: Was lighter and more durable than the traditional plaster cast and also resistant to water (though the bandages underneath were not) helping the patient be more active. In the 1990s the introduction of new cast lining has meant that fiberglass casts with this liner are completely waterproof, allowing patients to bathe, shower, and swim while wearing a cast. The waterproof cast liner however adds approximately two to three more minutes to
11880-687: Was never used for bandages. Ancient Hindus treated fractures with bamboo splints, and the writings of Hippocrates discuss management of fractures in some detail, recommending wooden splints plus exercise to prevent muscle atrophy during the immobilization. The ancient Greeks also used waxes and resins to create stiffened bandages and the Roman Celsus , writing in AD 30, describes how to use splints and bandages stiffened with starch. Arabian doctors used lime derived from sea shells and albumen from egg whites to stiffen bandages. The Italian School of Salerno in
11990-506: Was published on January 30, 1852; it was followed shortly by more complete accounts. In these accounts Mathijsen emphasised that only simple materials were required and the bandage could be quickly applied without assistance. The bandages hardened rapidly, provided an exact fit and could be windowed or bivalved (cut to provide strain relief) easily. Mathijsen used coarsely woven materials, usually linen, into which dry plaster of Paris had been rubbed thoroughly. The bandages were then moistened with
12100-443: Was the first type of glass used for fiberglass. E-glass ("E" because of initial Electrical application), is alkali-free and was the first glass formulation used for continuous filament formation. It now makes up most of the fiberglass production in the world, and also is the single largest consumer of boron minerals globally. It is susceptible to chloride ion attack and is a poor choice for marine applications. S-glass ("S" for "stiff")
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