wikipedia_id stringlengths 2 8 | wikipedia_title stringlengths 1 243 | url stringlengths 44 370 | contents stringlengths 53 2.22k | id int64 0 6.14M |
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43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
conductors to protect them from corrosion or wear. For instance, in 1902, steel cables supporting the Manhattan Bridge were first covered in linseed oil then wrapped in duck tape before being laid in place. In the 1910s, certain boots and shoes used canvas duck fabric for the upper or for the insole, and duck... | 6,400 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
tape that came without a layer of applied adhesive.
Adhesive tapes of various sorts were in use by the 1910s, including rolls of cloth tape with adhesive coating one side. White adhesive tape made of cloth soaked in rubber and zinc oxide was used in hospitals to bind wounds, but other tapes such as friction ... | 6,401 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
brand masking tape. In 1930, Drew developed a transparent tape based on cellophane, called Scotch Tape. This tape was widely used beginning in the Great Depression to repair household items. Author Scott Berkun has written that duct tape is "arguably" a modification of this early success by 3M. However, neith... | 6,402 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
at her factory. The letter was forwarded to the War Production Board, who put Johnson & Johnson on the job. The Revolite division of Johnson & Johnson had made medical adhesive tapes from duck cloth from 1927 and a team headed by Revolite's Johnny Denoye and Johnson & Johnson's Bill Gross developed the new ad... | 6,403 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
in army-standard matte olive drab, was widely used by the soldiers.
After the war, the duck tape product was sold in hardware stores for household repairs. The Melvin A. Anderson Company of Cleveland, Ohio, acquired the rights to the tape in 1950. It was commonly used in construction to wrap air ducts. Follo... | 6,404 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
holding together at .
In 1971, Jack Kahl bought the Anderson firm and renamed it Manco. In 1975, Kahl rebranded the duct tape made by his company. Because the previously used generic term "duck tape" had fallen out of use, he was able to trademark the brand "Duck Tape" and market his product complete with a ... | 6,405 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
with colorful, convenient packaging helped Duck Tape become popular. From a near-zero customer base Manco eventually controlled 40% of the duct tape market in the US. Acquired by Henkel in 1998, in 2009 Duck Tape was sold to Shurtape Technologies, which is owned by the Shuford family of North Carolina.
Duck ... | 6,406 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
1946 had developed the first practical vinyl electrical tape. By 1977, the company was selling a heat-resistant duct tape for heating ducts. In the late 1990s, 3M was running a $300 million duct tape division, the US industry leader. In 2004, 3M invented a transparent duct tape.
# Manufacture.
Modern duct t... | 6,407 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
into the LDPE. There are two commonly produced tape widths: and . Other widths are also offered. The largest commercial rolls of duct tape were made in 2005 for Henkel, with width, a roll diameter of and weighing .
# Common uses.
Duct tape is commonly used in situations that require a strong, flexible, and ... | 6,408 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
repair fiberglass bodywork (among other uses). Racer's tape comes in a wide range of colors to help match it to common paint colors. In the UK, it is usually referred to as "tank tape" in motorsports use.
## Usage on ductwork.
The product now commonly called duct tape should not be confused with special tap... | 6,409 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
seal ducts (they had defined duct tape as any fabric-based tape with rubber adhesive). The testing done shows that under challenging but realistic conditions, duct tapes become brittle and may fail quickly, at times becoming leaky or falling off completely.
Common duct tape carries no safety certifications s... | 6,410 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
engineer Jerry Woodfill, a 52-year NASA veteran, duct tape had been stowed on board every mission since early in the Gemini days.
NASA engineers and astronauts have used duct tape in the course of their work, including in some emergency situations. One such usage occurred in 1970 when Woodfill was working in... | 6,411 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
started working again, saving the lives of the three astronauts on board.
Ed Smylie, who designed the scrubber modification in just two days, said later that he knew the problem was solvable when it was confirmed that duct tape was on the spacecraft: "I felt like we were home free," he said in 2005. "One thi... | 6,412 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
cloth tape is called "EB Green," as the duct tape used by Electric Boat was green. It is also called "duck tape", "riggers' tape", "hurricane tape", or "100-mph tape"—a name that comes from the use of a specific variety of duct tape that was supposed to withstand up to winds. The tape is so named because it w... | 6,413 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
period. The evidence for its effectiveness is poor; thus it is not recommended as routine treatment. However, other studies suggest the duct tape treatment is more effective than existing medical options. Duct tape is often used in shoe repair due to its resiliency.
Duct tape has been used to temporarily fix... | 6,414 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
phrase in 1995 with the publication of their book about lubricant WD-40 book was, "Two rules get you through life: If it's stuck and it's not supposed to be, WD-40 it. If it's not stuck and it's supposed to be, duct tape it". Their website features thousands of duct tape uses from people around the world rang... | 6,415 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
series had a feature film based on it entitled "Duct Tape Forever" and several VHS/DVD compilations of the show's use of the tape have been released. Since 2000, series star Steve Smith (as "Red Green") has been the "Ambassador of Scotch Duct Tape" for 3M.
The Discovery Channel series "MythBusters" featured ... | 6,416 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
bridge that spanned the width of a dry dock, and a full-scale functional trebuchet with duct tape as the only binder. In the episode "Duct Tape Plane", the MythBusters repaired (and eventually replaced) the skin of a lightweight airplane with duct tape and flew it a few meters above a runway.
Garrison Keillo... | 6,417 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
kit", including duct tape and plastic (presumably to attempt to seal one's home against nuclear, chemical, and biological contaminants), among other items.
The recommendations came on the heels of an increase in the Department's official threat level to "orange", or "high risk", citing "recent intelligence r... | 6,418 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
Tape for Packaging, Box Closure, and Sealing, Type IV woven cloth backing
- ASTM D580 Standard Specification for Greige Woven Glass Tapes and Webbings
- ASTM D4514-12 Standard Specification for Friction Tape
- ASTM D2754-10 Standard Specification for High-Temperature Glass Cloth Pressure-Sensitive Electric... | 6,419 |
43707 | Duct tape | https://en.wikipedia.org/w/index.php?title=Duct%20tape | Duct tape
M D4514-12 Standard Specification for Friction Tape
- ASTM D2754-10 Standard Specification for High-Temperature Glass Cloth Pressure-Sensitive Electrical Insulating Tape
- MODUK DEF STAN 81-25, EN-Tape Pressure-Sensitive Adhesive (Water Resistant Fabric)
- McDonnell-Douglas DMS1968E
- Lockheed LCP-86-1226... | 6,420 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
Radiation pressure
Radiation pressure is the pressure exerted upon any surface due to the exchange of momentum between the object and the electromagnetic field. This includes the momentum of light or electromagnetic radiation of any wavelength which is absorbed, reflected, or otherwise emitted (e.g.... | 6,421 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
where the net effect of a tiny force may have a large cumulative effect over long periods of time. For example, had the effects of the sun's radiation pressure on the spacecraft of the Viking program been ignored, the spacecraft would have missed Mars orbit by about . Radiation pressure from starligh... | 6,422 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
of photons, particles of light. The interaction of electromagnetic waves or photons with matter may involve an exchange of momentum. Due to the law of conservation of momentum, any change in the total momentum of the waves or photons must involve an equal and opposite change in the momentum of the ma... | 6,423 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
points away from the Sun.
The assertion that light, as electromagnetic radiation, has the property of momentum and thus exerts a pressure upon any surface it is exposed to was published by James Clerk Maxwell in 1862, and proven experimentally by Russian physicist Pyotr Lebedev in 1900 and by Ernest... | 6,424 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
as a consequence of the conservation of momentum given the momentum attributed to electromagnetic radiation. That momentum can be equally well calculated on the basis of electromagnetic theory or from the combined momenta of a stream of photons, giving identical results as is shown below.
## Radiati... | 6,425 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
per unit area (pressure) of the electromagnetic field. So, dimensionally, the Poynting vector is S=(power/area)=(rate of doing work/area)=(ΔF/Δt)Δx/area, which is the speed of light, c=Δx/Δt, times pressure, ΔF/area. That pressure is experienced as radiation pressure on the surface:
where formula_3 ... | 6,426 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
in a pressure:
The momentum from the incident wave is in the same direction of that wave. But only the component of that momentum normal to the surface contributes to the pressure on the surface, as given above. The component of that force tangent to the surface is not called pressure.
## Radiation... | 6,427 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
"doubling" the net radiation pressure on the surface:
For a partially reflective surface, the second term must be multiplied by the reflectivity (also known as reflection coefficient of intensity), so that the increase is less than double. For a diffusely reflective surface, the details of the refle... | 6,428 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
direction normal to the surface" "I":
The emission can be from black-body radiation or any other radiative mechanism. Since all materials emit black-body radiation (unless they are totally reflective or at absolute zero), this source for radiation pressure is ubiquitous but usually very tiny. Howeve... | 6,429 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
Radiation pressure in terms of photons.
Electromagnetic radiation can be viewed in terms of particles rather than waves; these particles are known as photons. Photons do not have a rest-mass; however, photons are never at rest (they move at the speed of light) and acquire a momentum nonetheless whic... | 6,430 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
"I" over an area "A" has a power of "IA", this implies a flux of "I/E" photons per second per unit area striking the surface. Combining this with the above expression for the momentum of a single photon, results in the same relationships between irradiance and radiation pressure described above using... | 6,431 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
per unit volume.
This can also be shown in the specific case of the pressure exerted on surfaces of a body in thermal equilibrium with its surroundings, at a temperature "T": The body will be surrounded by a uniform radiation field described by the Planck black-body radiation law, and will experienc... | 6,432 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
pressure is due to the sun's radiation at closer distances, thus especially within the Solar System. While it acts on all objects, its net effect is generally greater on smaller bodies since they have a larger ratio of surface area to mass. All spacecraft experience such a pressure except when they a... | 6,433 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
must be taken into account when calculating the radiation pressure or identifying reflector materials for optimizing a solar sail for instance.
## Pressures of absorption and reflection.
Solar radiation pressure at the earth's distance from the sun, may be calculated by dividing the solar constant ... | 6,434 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
another cosine factor must be applied resulting in a pressure "P" on the surface of:
Note, however, that in order to account for the net effect of solar radiation on a spacecraft for instance, one would need to consider the "total" force (in the direction away from the sun) given by the preceding eq... | 6,435 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
perfectly reflecting surface, the pressure is "doubled" due to the reflected wave, resulting in:
Note that unlike the case of an absorbing material, the resulting force on a reflecting body is given exactly by this pressure acting normal to the surface, with the tangential forces from the incident a... | 6,436 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
spacecraft.
Solar radiation pressure affects bodies throughout much of the Solar System. Small bodies are more affected than large ones because of their lower mass relative to their surface area. Spacecraft are affected along with natural bodies (comets, asteroids, dust grains, gas molecules).
The ... | 6,437 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
numerous surfaces that have different orientations on the body. The facets may be flat or curved. They will have different areas. They may have optical properties differing from other aspects.
At any particular time, some facets will be exposed to the Sun and some will be in shadow. Each surface exp... | 6,438 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
at a higher temperature than a face approaching solar exposure. The radiation emitted from the warmer face will be more intense than that of the opposite face, resulting in a net force on the body that will affect its motion.
The YORP effect is a collection of effects expanding upon the earlier conc... | 6,439 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
the direction of movement. (The angle of aberration is tiny since the radiation is moving at the speed of light while the dust grain is moving many orders of magnitude slower than that.) The result is a gradual spiral of dust grains into the Sun. Over long periods of time, this effect cleans out much... | 6,440 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
the ratio of surface area to volume (and thus mass) increases with decreasing particle size, dusty (micrometre-size) particles are susceptible to radiation pressure even in the outer solar system. For example, the evolution of the outer rings of Saturn is significantly influenced by radiation pressur... | 6,441 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
motion (front surface) than on the back surface. The backward acting force of pressure exerted on the front surface is thus larger than the force of pressure acting on the back. Hence, as the resultant of the two forces, there remains a force that counteracts the motion of the plate and that increase... | 6,442 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
that is absorbed is radiated away from both surfaces, with the proportion emitted from the unlit surface depending on the thermal conductivity of the sail. A sail has curvature, surface irregularities, and other minor factors that affect its performance.
The Japan Aerospace Exploration Agency (JAXA)... | 6,443 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
photon epoch is a phase when the energy of the universe was dominated by photons, between 10 seconds and 380,000 years after the Big Bang.
## Galaxy formation and evolution.
The process of galaxy formation and evolution began early in the history of the cosmos. Observations of the early universe st... | 6,444 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
pressure, especially when the condensations lead to star births. The larger young stars forming within the compressed clouds emit intense levels of radiation that shift the clouds, causing either dispersion or condensations in nearby regions, which influences birth rates in those nearby regions.
## ... | 6,445 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
of the constituent stars. These clusters will rapidly disperse within a few million years. In many cases, the stripping away of the gas from which the cluster formed by the radiation pressure of the hot young stars reduces the cluster mass enough to allow rapid dispersal.
## Star formation.
Star fo... | 6,446 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
for the formation of a single star, must also account for the statistics of binary stars and the initial mass function.
## Stellar planetary systems.
Planetary systems are generally believed to form as part of the same process that results in star formation. A protoplanetary disk forms by gravitati... | 6,447 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
the stellar system under the action of radiation pressure.
## Stellar interiors.
In stellar interiors the temperatures are very high. Stellar models predict a temperature of 15 MK in the center of the Sun, and at the cores of supergiant stars the temperature may exceed 1 GK. As the radiation pressu... | 6,448 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
nucleus, which also carry away dust grains. Radiation pressure and solar wind then drive the dust and gases away from the Sun's direction. The gases form a generally straight tail, while slower moving dust particles create a broader, curving tail.
# Laser applications of radiation pressure.
## Opti... | 6,449 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
is applied to cooling materials very close to absolute zero. Atoms traveling towards a laser light source perceive a doppler effect tuned to the absorption frequency of the target element. The radiation pressure on the atom slows movement in a particular direction until the Doppler effect moves out o... | 6,450 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
radiation pressure acting during the reflection of the light. Recently, such light-pressure-induced elastic waves were observed inside an ultrahigh-reflectivity dielectric mirror. These waves are the most basic fingerprint of a light-solid matter interaction on the macroscopic scale.
# See also.
- ... | 6,451 |
43709 | Radiation pressure | https://en.wikipedia.org/w/index.php?title=Radiation%20pressure | Radiation pressure
light. Recently, such light-pressure-induced elastic waves were observed inside an ultrahigh-reflectivity dielectric mirror. These waves are the most basic fingerprint of a light-solid matter interaction on the macroscopic scale.
# See also.
- Absorption (electromagnetic radiation)
- Photon
- Poy... | 6,452 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
Silicon dioxide
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and most abundant fam... | 6,453 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
of the lung tissue, silicosis, bronchitis, lung cancer, and systemic autoimmune diseases, such as lupus and rheumatoid arthritis.
Inhalation of amorphous silicon dioxide, in high doses, leads to non-permanent short-term inflammation, where all effects heal.
# Structure.
In the majority of silicates, ... | 6,454 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
the two face-centered tetrahedra share two of their corner O atoms, and the four edge-centered tetrahedra share just one of their O atoms with other SiO tetrahedra. This leaves a net average of 12 out of 24 total vertices for that portion of the seven SiO tetrahedra that are considered to be a part of t... | 6,455 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
α-quartz the bond length is 161 pm, whereas in α-tridymite it is in the range 154–171 pm. The Si-O-Si angle also varies between a low value of 140° in α-tridymite, up to 180° in β-tridymite. In α-quartz, the Si-O-Si angle is 144°.
Fibrous silica has a structure similar to that of SiS with chains of edg... | 6,456 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
(four Si-O bond lengths of 176 pm and two others of 181 pm) are greater than the Si-O bond length (161 pm) in α-quartz.
The change in the coordination increases the ionicity of the Si-O bond. More importantly, any deviations from these standard parameters constitute microstructural differences or varia... | 6,457 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
than quartz. Since the composition is identical, the reason for the discrepancies must be in the increased spacing in the high-temperature minerals. As is common with many substances, the higher the temperature, the farther apart the atoms are, due to the increased vibration energy.
The transformation ... | 6,458 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
compression of the atoms occurring during their formation, resulting in more condensed structure.
Faujasite silica is another form of crystalline silica. It is obtained by dealumination of a low-sodium, ultra-stable Y zeolite with combined acid and thermal treatment. The resulting product contains over... | 6,459 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
temperature expansion, density maximum at temperatures ~5000 °C, and a heat capacity minimum. Its density decreases from 2.08 g/cm at 1950 °C to 2.03 g/cm at 2200 °C.
Molecular SiO with a linear structure is produced when molecular silicon monoxide, SiO, is condensed in an argon matrix cooled with heli... | 6,460 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
148.3 pm, which compares with the length of 161 pm in α-quartz. The bond energy is estimated at 621.7 kJ/mol.
# Natural occurrence.
## Geology.
Silica with the chemical formula is most commonly found in nature as quartz, which comprises more than 10% by mass of the earth's crust. Quartz is the only p... | 6,461 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
of sand.
## Biology.
Even though it is poorly soluble, silica occurs in many plants. Plant materials with high silica phytolith content appear to be of importance to grazing animals, from chewing insects to ungulates. Silica accelerates tooth wear, and high levels of silica in plants frequently eaten ... | 6,462 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
and vertebrates).
Prominent examples include:
- Tests or frustules (i.e. shells) of diatoms, Radiolaria and testate amoebae.
- Silica phytoliths in the cells of many plants, including Equisetaceae, practically all grasses, and a wide range of dicotyledons.
- The spicules forming the skeleton of many... | 6,463 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
low temperature (0–40 °C).
Formation of the mineral may occur either within the cell wall of an organism (such as with phytoliths), or outside the cell wall, as typically happens with tests. Specific biochemical reactions exist for mineral deposition. Such reactions include those that involve lipids, p... | 6,464 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
This makes it difficult to be sure when the silica present has had operative beneficial effects, and when its presence is coincidental, or even harmful. The current consensus is that it certainly seems important in the growth, strength, and management of many connective tissues. This is true not only fo... | 6,465 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
for the manufacture of metallic components in engineering and other applications. The high melting point of silica enables it to be used in such applications.
Crystalline silica is used in hydraulic fracturing of formations which contain tight oil and shale gas.
## Precursor to glass and silicon.
Sil... | 6,466 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
tetrahedra of oxygen centers. The difference between the glass and crystalline forms arises from the connectivity of the tetrahedral units: Although there is no long range periodicity in the glassy network ordering remains at length scales well beyond the SiO bond length. One example of this ordering is... | 6,467 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
such as earthenware, stoneware, and porcelain.
Silicon dioxide is used to produce elemental silicon. The process involves carbothermic reduction in an electric arc furnace:
## Food and pharmaceutical applications.
Silica is a common additive in food production, where it is used primarily as a flow ag... | 6,468 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
formed.
## Personal care.
In cosmetics, it is useful for its light-diffusing properties and natural absorbency.
Hydrated silica is used in toothpaste as a hard abrasive to remove tooth plaque.
## Other.
Hydrophobic silica is used as a defoamer component.
In its capacity as a refractory, it is usef... | 6,469 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
can be used as a glass fiber for fiberglass.
# Production.
Silicon dioxide is mostly obtained by mining, including sand mining and purification of quartz.
Quartz is suitable for many purposes, while chemical processing is required to make a purer or otherwise more suitable (e.g. more reactive or fine... | 6,470 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
silica is produced by the acidification of solutions of sodium silicate. The gelatinous precipitate or silica gel, is first washed and then dehydrated to produce colorless microporous silica. The idealized equation involving a trisilicate and sulfuric acid is:
Approximately one billion kilograms/year (... | 6,471 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
on silicon, for example at temperatures between 600 and 1200 °C, using so-called dry or wet oxidation with O
or HO, respectively.
The native oxide layer is beneficial in microelectronics, where it acts as electric insulator with high chemical stability. It can protect the silicon, store charge, block ... | 6,472 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
400 °C:
TEOS undergoes hydrolysis via the so-called sol-gel process. The course of the reaction and nature of the product are affected by catalysts, but the idealized equation is:
### Other methods.
Being highly stable, silicon dioxide arises from many methods. Conceptually simple, but of little prac... | 6,473 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
and O whereas the other halogen gases (Cl, Br, I) are essentially unreactive.
Silicon dioxide is attacked by hydrofluoric acid (HF) to produce hexafluorosilicic acid:
HF is used to remove or pattern silicon dioxide in the semiconductor industry.
Under normal conditions, silicon does not react with mo... | 6,474 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
in plastic bottles as a result.
Silicon dioxide dissolves in hot concentrated alkali or fused hydroxide, as described in this idealized equation:
Silicon dioxide will neutralise basic metal oxides (e.g. sodium oxide, potassium oxide, lead(II) oxide, zinc oxide, or mixtures of oxides, forming silicates... | 6,475 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
former. The reaction is also used in blast furnaces to remove sand impurities in the ore by neutralisation with calcium oxide, forming calcium silicate slag.
Silicon dioxide reacts in heated reflux under dinitrogen with ethylene glycol and an alkali metal base to produce highly reactive, pentacoordinat... | 6,476 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
as a function of temperature, it peaks around 340 °C. This property is used to grow single crystals of quartz in a hydrothermal process where natural quartz is dissolved in superheated water in a pressure vessel that is cooler at the top. Crystals of 0.5–1 kg can be grown over a period of 1–2 months. T... | 6,477 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
risk of dementia of 11%.
Inhaling finely divided crystalline silica dust can lead to silicosis, bronchitis, or lung cancer, as the dust becomes lodged in the lungs and continuously irritates the tissue, reducing lung capacities. When fine silica particles are inhaled in large enough quantities (such as... | 6,478 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
lung damage in some cases, but is not associated with development of silicosis. Children, asthmatics of any age, those with allergies, and the elderly (all of whom have reduced lung capacity) can be affected in less time.
Crystalline silica is an occupational hazard for those working with stone counter... | 6,479 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
and dendritic cells and thereby result in production of interleukin, a highly pro-inflammatory cytokine in the immune system.
## Regulation.
Regulations restricting silica exposure 'with respect to the silicosis hazard' specify that they are concerned only with silica, which is both crystalline and du... | 6,480 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
almost any material, exists in many crystalline forms. These forms are called polymorphs.
# See also.
- Mesoporous silica
- Silicon carbide
# External links.
- Tridymite,
- Quartz,
- Cristobalite,
- amorphous, NIOSH Pocket Guide to Chemical Hazards
- crystalline, as respirable dust, NIOSH Pocke... | 6,481 |
43710 | Silicon dioxide | https://en.wikipedia.org/w/index.php?title=Silicon%20dioxide | Silicon dioxide
ket Guide to Chemical Hazards
- Formation of silicon oxide layers in the semiconductor industry. LPCVD and PECVD method in comparison. Stress prevention.
- Quartz SiO piezoelectric properties
- Silica (SiO) and Water
- Epidemiological evidence on the carcinogenicity of silica: factors in scientific ... | 6,482 |
43720 | Hammer throw | https://en.wikipedia.org/w/index.php?title=Hammer%20throw | Hammer throw
Hammer throw
The hammer throw is one of the four throwing events in regular track and field competitions, along with the discus throw, shot put and javelin. The "hammer" used in this sport is not like any of the tools also called by that name. It consists of a metal ball attached by a steel wire to a grip... | 6,483 |
43720 | Hammer throw | https://en.wikipedia.org/w/index.php?title=Hammer%20throw | Hammer throw
legacy prior to inclusion in the Olympics have been dominated by European and Eastern European influence, which has affected interest in the event in other parts of the world.
The hammer evolved from its early informal origins to become part of the Scottish Highland games in the late 18th century, where t... | 6,484 |
43720 | Hammer throw | https://en.wikipedia.org/w/index.php?title=Hammer%20throw | Hammer throw
a year earlier.
# Competition.
The men's hammer weighs and measures in length, and the women's hammer weighs and in length. Like the other throwing events, the competition is decided by who can throw the implement the farthest.
Although commonly thought of as a strength event, technical advancements in ... | 6,485 |
43720 | Hammer throw | https://en.wikipedia.org/w/index.php?title=Hammer%20throw | Hammer throw
with each turn with the high point of the hammer ball toward the target sector and the low point at the back of the circle. The thrower releases the ball from the front of the circle.
The world record for the women's hammer is held by Anita Włodarczyk, who threw during the Kamila Skolimowska Memorial on 2... | 6,486 |
43720 | Hammer throw | https://en.wikipedia.org/w/index.php?title=Hammer%20throw | Hammer throw
annulled due to drugs disqualification.
## Women.
- Correct as of July 2019.
### Notes.
Below is a list of throws equal or superior to 78.00 m:
- Anita Włodarczyk also threw 82.87 m (2017), 82.29 m (2016), 81.77 m (2016), 81.74 (2016), 81.63 m (2017), 81.27 m (2016), 81.08 m (2015), 80.85 m (2015), 80... | 6,487 |
43720 | Hammer throw | https://en.wikipedia.org/w/index.php?title=Hammer%20throw | Hammer throw
m (2018), 78.76 m (2014), 78.74 m (2018), 78.69 m (2016), 78.59 m (2017), 78.55 m (2018), 78.54 m (2016), 78.52 m (2017), 78.46 m (2013), 78.35 m (2017), 78.30 m (2010), 78.28 m (2015), 78.24 m (2015), 78.22 m (2013), 78.17 m (2014), 78.16 m (2015), 78.14 m (2016), 78.10 (2016), 78.00 m (2017).
- Tatyana ... | 6,488 |
43720 | Hammer throw | https://en.wikipedia.org/w/index.php?title=Hammer%20throw | Hammer throw
4 m (2016), 78.10 (2016), 78.00 m (2017).
- Tatyana Lysenko also threw 78.51 m (2012) and 78.15 m (2013)
- Betty Heidler also threw 78.07 m (2012) and 78.00 m (2014).
### Non-legal marks.
The following athletes had their performances (over 77.00 m) annulled due to doping offences:
- Aksana Miankova (B... | 6,489 |
74561 | Saint Jerome (disambiguation) | https://en.wikipedia.org/w/index.php?title=Saint%20Jerome%20(disambiguation) | Saint Jerome (disambiguation)
Saint Jerome (disambiguation)
Saint Jerome is a Christian church father, best known for translating the Bible into Latin.
Saint Jerome may also refer to:
# People.
- Jerome of Pavia (fl. 778–787), Bishop of Pavia
- Saint Jerome Emiliani (1486–1537), Italian humanitarian, founder of th... | 6,490 |
74561 | Saint Jerome (disambiguation) | https://en.wikipedia.org/w/index.php?title=Saint%20Jerome%20(disambiguation) | Saint Jerome (disambiguation)
Jérôme (AMT), a bus and train station
- St. Jerome Church (disambiguation), several churches
# Arts.
- Francesco "St Jerome", a c. 1595 oil painting on copper attributed to the circle of Palma the Younger
- "Saint Jerome in His Study" (after van Eyck), a 1442 painting
- "Saint Jerome ... | 6,491 |
43675 | Laurence Olivier | https://en.wikipedia.org/w/index.php?title=Laurence%20Olivier | Laurence Olivier
Laurence Olivier
Laurence Kerr Olivier, Baron Olivier, (; 22 May 1907 – 11 July 1989) was an English actor and director who, along with his contemporaries Ralph Richardson, Peggy Ashcroft and John Gielgud, dominated the British stage of the mid-20th century. He also worked in films throughout his care... | 6,492 |
43675 | Laurence Olivier | https://en.wikipedia.org/w/index.php?title=Laurence%20Olivier | Laurence Olivier
success in Noël Coward's "Private Lives", and he appeared in his first film. In 1935 he played in a celebrated production of "Romeo and Juliet" alongside Gielgud and Ashcroft, and by the end of the decade he was an established star. In the 1940s, together with Richardson and John Burrell, Olivier was t... | 6,493 |
43675 | Laurence Olivier | https://en.wikipedia.org/w/index.php?title=Laurence%20Olivier | Laurence Olivier
film. From 1963 to 1973 he was the founding director of Britain's National Theatre, running a resident company that fostered many future stars. His own parts there included the title role in "Othello" (1965) and Shylock in "The Merchant of Venice" (1970).
Among Olivier's films are "Wuthering Heights" ... | 6,494 |
43675 | Laurence Olivier | https://en.wikipedia.org/w/index.php?title=Laurence%20Olivier | Laurence Olivier
"Love Among the Ruins" (1975), "Cat on a Hot Tin Roof" (1976), "Brideshead Revisited" (1981) and "King Lear" (1983).
Olivier's honours included a knighthood (1947), a life peerage (1970) and the Order of Merit (1981). For his on-screen work he received four Academy Awards, two British Academy Film Awa... | 6,495 |
43675 | Laurence Olivier | https://en.wikipedia.org/w/index.php?title=Laurence%20Olivier | Laurence Olivier
Family background and early life (1907–1924).
Olivier was born in Dorking, Surrey, the youngest of the three children of the Reverend Gerard Kerr Olivier (1869–1939) and his wife Agnes Louise, "née" Crookenden (1871–1920). Their elder children were Sybille (1901–1989) and Gerard Dacres "Dickie" (1904–... | 6,496 |
43675 | Laurence Olivier | https://en.wikipedia.org/w/index.php?title=Laurence%20Olivier | Laurence Olivier
This made him unacceptable to most Anglican congregations, and the only church posts he was offered were temporary, usually deputising for regular incumbents in their absence. This meant a nomadic existence, and for Laurence's first few years, he never lived in one place long enough to make friends.
I... | 6,497 |
43675 | Laurence Olivier | https://en.wikipedia.org/w/index.php?title=Laurence%20Olivier | Laurence Olivier
had considered a stage career and was a dramatic and effective preacher. Olivier wrote that his father knew "when to drop the voice, when to bellow about the perils of hellfire, when to slip in a gag, when suddenly to wax sentimental ... The quick changes of mood and manner absorbed me, and I have neve... | 6,498 |
43675 | Laurence Olivier | https://en.wikipedia.org/w/index.php?title=Laurence%20Olivier | Laurence Olivier
emphasis on ritual, vestments and incense. The theatricality of the services appealed to Olivier, and the vicar encouraged the students to develop a taste for secular as well as religious drama. In a school production of "Julius Caesar" in 1917, the ten-year-old Olivier's performance as Brutus impresse... | 6,499 |
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