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Quartz Fiber
Quartz fiber is a fiber created from high-purity quartz crystals. It is made by first softening quartz rods (in an oxyhydrogen flame) and then creating filaments from the rods. Since the creation of high-purity quartz crystals is an energy intensive process, quartz fiber is more expensive than alternatives (glass fiber and high-silica fiber) and has limited applications. Manufacture Quartz fiber is made from heating quartz rods with an oxyhydrogen flame. Then, filaments are drawn out of the quartz rod, creating quartz fibers. For optical fibers, germanium and phosphorus can be added to increase the refractive index. Properties A single quartz fiber can have a tensile strength of . Quartz fibers are chemically stable as they are not affected by halogens (for the most part). Quartz fibers also have a higher thermal resistance than S-glass or E-glass. Applications Since quartz fiber is expensive, it has limited applications. It is used mainly for producing composite mat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fiber
Fiber (spelled fibre in British English; from ) is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often incorporate fibers, for example carbon fiber and ultra-high-molecular-weight polyethylene. Synthetic fibers can often be produced very cheaply and in large amounts compared to natural fibers, but for clothing natural fibers have some benefits, such as comfort, over their synthetic counterparts. Natural fibers Natural fibers develop or occur in the fiber shape, and include those produced by plants, animals, and geological processes. They can be classified according to their origin: * Vegetable fibers are generally based on arrangements of cellulose, often with lignin: examples include cotton, hemp, jute, flax, abaca, piña, ramie, sisal, bagasse, and banana. Plant fibers are employed in the manufacture of paper and textile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Resistance
In heat transfer, thermal engineering, and thermodynamics, thermal conductance and thermal resistance are fundamental concepts that describe the ability of materials or systems to conduct heat and the opposition they offer to the heat current. The ability to manipulate these properties allows engineers to control temperature gradient, prevent thermal shock, and maximize the efficiency of thermal systems. Furthermore, these principles find applications in a multitude of fields, including materials science, mechanical engineering, electronics, and energy management. Knowledge of these principles is crucial in various scientific, engineering, and everyday applications, from designing efficient temperature control, thermal insulation, and thermal management in industrial processes to optimizing the performance of electronic devices. Thermal conductance (''G'') measures the ability of a material or system to conduct heat. It provides insights into the ease with which heat can pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz Fiber Dosimeter
A quartz fiber dosimeter, sometimes called a self indicating pocket dosimeter (SIPD) or self reading pocket dosimeter (SRPD) or quartz fibre electrometer (QFE), is a type of radiation dosimeter, a pen-like device that measures the cumulative dose of ionizing radiation received by the device, usually over one work period. It is clipped to a person's clothing, normally a breast pocket for whole body exposure, to measure the user's exposure to radiation. It is now being superseded by more modern dosimeter types such as the electronic personal dosimeter (EPD). Use As with other types of personal radiation dosimeter, it is worn by workers who are occupationally exposed to radiation, so their employers can keep a record of their exposure, to verify that it is below legally prescribed limits. It works by measuring the decrease in electrostatic charge on a metal conductor in an ionization chamber, due to ionization of the air in the chamber by radiation. It was invented in 193 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fused Quartz
Fused quartz, fused silica or quartz glass is a glass consisting of almost pure silica (silicon dioxide, SiO2) in amorphous (non-crystalline) form. This differs from all other commercial glasses, such as soda-lime glass, lead glass, or borosilicate glass, in which other ingredients are added which change the glasses' optical and physical properties, such as lowering the melt temperature, the spectral transmission range, or the mechanical strength. Fused quartz, therefore, has high working and melting temperatures, making it difficult to form and less desirable for most common applications, but is much stronger, more chemically resistant, and exhibits lower thermal expansion, making it more suitable for many specialized uses such as lighting and scientific applications. The terms ''fused quartz'' and ''fused silica'' are used interchangeably but can refer to different manufacturing techniques, resulting in different trace impurities. However fused quartz, being in the glassy s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three-dimensional Quartz Phenolic
Three-dimensional quartz phenolic (3DQP) is a phenolic-based material composed of a quartz cloth material impregnated with a phenolic resin and hot-pressed. When cured, 3DQP can be machined in the same way as metals and is tough and fire-resistant. 3DQP is used for the manufacture of nuclear weapon re-entry vehicles (RV). The quartz material ' hardens' the RV protecting the nuclear warhead against high-energy neutrons emitted by exo-atmospheric Anti-ballistic missile (ABM) bursts before re-entry. 3DQP was first used on the British Chevaline improved front end (IFE) for the Royal Navy's UGM-27 Polaris system that was in service from 1982 to 1996, when it was replaced by Trident D5. Manufacture A licence to manufacture 3DQP in the US was acquired from the British Government and production was undertaken by AVCO, one of the two suppliers of US RVs, the other being General Electric. First production examples of the Chevaline ReBs were manufactured by AVCO, now part of Textron. Subs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fiberglass
Fiberglass (American English) or fibreglass (English in the Commonwealth of Nations, Commonwealth English) is a common type of fibre-reinforced plastic, fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cloth. The plastic Matrix (composite), 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-reinforced polymers, 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 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decibel
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a Power, root-power, and field quantities, power or root-power quantity on a logarithmic scale. Two signals whose level (logarithmic quantity), levels differ by one decibel have a power ratio of 101/10 (approximately ) or root-power ratio of 101/20 (approximately ). The strict original usage above only expresses a relative change. However, the word decibel has since also been used for expressing an Absolute scale, absolute value that is relative to some fixed reference value, in which case the dB symbol is often suffixed with letter codes that indicate the reference value. For example, for the reference value of 1 volt, a common suffix is "#Voltage, V" (e.g., "20 dBV"). As it originated from a need to express power ratios, two principal types of scaling of the decibel are used to provide consistency depending on whether the scaling refer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmission (telecommunications)
In telecommunications, transmission (sometimes abbreviated as "TX") is the process of sending or propagating an Analog signal, analog or digital signal via a transmission medium, medium that is wired communication, wired, wireless, or fiber-optic communication, fiber-optic. Transmission system technologies typically refer to physical layer protocol duties such as modulation, demodulation, line coding, Equalization (communications), equalization, error control, bit synchronization and multiplexing, but it may also involve higher-layer protocol duties, for example, digitizing an analog signal, and data compression. Transmission of a digital message, or of a digitized analog signal, is known as data transmission. Examples of transmission are the sending of signals with limited duration, for example, a block or Network packet, packet of data, a phone call, or an email. See also *Radio transmitter References Telecommunications engineering {{telecom-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terabit
The bit is the most basic unit of information in computing and digital communication. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represented as either , but other representations such as ''true''/''false'', ''yes''/''no'', ''on''/''off'', or ''+''/''−'' are also widely used. The relation between these values and the physical states of the underlying storage or device is a matter of convention, and different assignments may be used even within the same device or program. It may be physically implemented with a two-state device. A contiguous group of binary digits is commonly called a '' bit string'', a bit vector, or a single-dimensional (or multi-dimensional) ''bit array''. A group of eight bits is called one ''byte'', but historically the size of the byte is not strictly defined. Frequently, half, full, double and quadruple words consist of a number of bytes which is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data (computing)
''In computer science, data (treated as singular, plural, or as a mass noun) is any sequence of one or more symbols; datum is a single symbol of data. Data requires interpretation to become information. Digital data is data that is represented using the binary number system of ones (1) and zeros (0), instead of analog representation. In modern (post-1960) computer systems, all data is digital.'' Data exists in three states: data at rest, data in transit and data in use. Data within a computer, in most cases, moves as parallel data. Data moving to or from a computer, in most cases, moves as serial data. Data sourced from an analog device, such as a temperature sensor, may be converted to digital using an analog-to-digital converter. Data representing quantities, characters, or symbols on which operations are performed by a computer are stored and recorded on magnetic, optical, electronic, or mechanical recording media, and transmitted in the form of digital elec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz Fiber Dosimeter
A quartz fiber dosimeter, sometimes called a self indicating pocket dosimeter (SIPD) or self reading pocket dosimeter (SRPD) or quartz fibre electrometer (QFE), is a type of radiation dosimeter, a pen-like device that measures the cumulative dose of ionizing radiation received by the device, usually over one work period. It is clipped to a person's clothing, normally a breast pocket for whole body exposure, to measure the user's exposure to radiation. It is now being superseded by more modern dosimeter types such as the electronic personal dosimeter (EPD). Use As with other types of personal radiation dosimeter, it is worn by workers who are occupationally exposed to radiation, so their employers can keep a record of their exposure, to verify that it is below legally prescribed limits. It works by measuring the decrease in electrostatic charge on a metal conductor in an ionization chamber, due to ionization of the air in the chamber by radiation. It was invented in 193 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dielectric
In electromagnetism, a dielectric (or dielectric medium) is an Insulator (electricity), electrical insulator that can be Polarisability, polarised by an applied electric field. When a dielectric material is placed in an electric field, electric charges do not flow through the material as they do in an electrical conductor, because they have no loosely bound, or free, electrons that may drift through the material, but instead they shift, only slightly, from their average equilibrium positions, causing dielectric polarisation. Because of Polarisation density, dielectric polarisation, positive charges are displaced in the direction of the field and negative charges shift in the direction opposite to the field. This creates an internal electric field that reduces the overall field within the dielectric itself. If a dielectric is composed of weakly Chemical bond, bonded molecules, those molecules not only become polarised, but also reorient so that their Symmetry axis, symmetry axes a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
