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Fuse (electrical)

In electronics and electrical engineering, a fuse is an electrical safety device that operates to provide overcurrent protection of an electrical circuit. Its essential component is a metal wire or strip that melts when too much current flows through it, thereby stopping or interrupting the current. It is a sacrificial device; once a fuse has operated, it is an open circuit, and must be replaced or rewired, depending on its type.

Fuses have been used as essential safety devices from the early days of electrical engineering. Today there are thousands of different fuse designs which have specific current and voltage ratings, breaking capacity, and response times, depending on the application. The time and current operating characteristics of fuses are chosen to provide adequate protection without needless interruption. Wiring regulations usually define a maximum fuse current rating for particular circuits. Short circuits, overloading, mismatched loads, or device failure are the prime or some of the reasons for fuse operation. When a damaged live wire makes contact with a metal case that is connected to ground, a short circuit will form and the fuse will melt.

A fuse is an automatic means of removing power from a faulty system; often abbreviated to ADS (Automatic Disconnection of Supply). Circuit breakers can be used as an alternative to fuses, but have significantly different characteristics.

History
Breguet recommended the use of reduced-section conductors to protect telegraph stations from lightning strikes; by melting, the smaller wires would protect apparatus and wiring inside the building. A variety of wire or foil fusible elements were in use to protect telegraph cables and lighting installations as early as 1864.

A fuse was patented by Thomas Edison in 1890 as part of his electric distribution system.

Construction
A fuse consists of a metal strip or wire fuse element, of small cross-section compared to the circuit conductors, mounted between a pair of electrical terminals, and (usually) enclosed by a non-combustible housing. The fuse is arranged in series to carry all the charge passing through the protected circuit. The resistance of the element generates heat due to the current flow. The size and construction of the element is (empirically) determined so that the heat produced for a normal current does not cause the element to attain a high temperature. If too high a current flows, the element rises to a higher temperature and either directly melts, or else melts a soldered joint within the fuse, opening the circuit.

The fuse element is made of zinc, copper, silver, aluminum, or alloys among these or other various metals to provide stable and predictable characteristics. The fuse ideally would carry its rated current indefinitely, and melt quickly on a small excess. The element must not be damaged by minor harmless surges of current, and must not oxidize or change its behavior after possibly years of service.

The fuse elements may be shaped to increase heating effect. In large fuses, current may be divided between multiple strips of metal. A dual-element fuse may contain a metal strip that melts instantly on a short circuit, and also contain a low-melting solder joint that responds to long-term overload of low values compared to a short circuit. Fuse elements may be supported by steel or nichrome wires, so that no strain is placed on the element, but a spring may be included to increase the speed of parting of the element fragments.

The fuse element may be surrounded by air, or by materials intended to speed the quenching of the arc. Silica sand or non-conducting liquids may be used.

Rated current IN
A maximum current that the fuse can continuously conduct without interrupting the circuit.

Time vs current characteristics
The speed at which a fuse blows depends on how much current flows through it and the material of which the fuse is made. Manufacturers can provide a plot of current vs time, often plotted on logarithmic scales, to characterize the device and to allow comparison with the characteristics of protective devices upstream and downstream of the fuse.

The operating time is not a fixed interval but decreases as the current increases. Fuses are designed to have particular characteristics of operating time compared to current. A standard fuse may require twice its rated current to open in one second, a fast-blow fuse may require twice its rated current to blow in 0.1 seconds, and a slow-blow fuse may require twice its rated current for tens of seconds to blow.

Fuse selection depends on the load's characteristics. Semiconductor devices may use a fast or ultrafast fuse as semiconductor devices heat rapidly when excess current flows. The fastest blowing fuses are designed for the most sensitive electrical equipment, where even a short exposure to an overload current could be damaging. Normal fast-blow fuses are the most general purpose fuses. A time-delay fuse (also known as an anti-surge or slow-blow fuse) is designed to allow a current which is above the rated value of the fuse to flow for a short period of time without the fuse blowing. These types of fuse are used on equipment such as motors, which can draw larger than normal currents for up to several seconds while coming up to speed.

The I2t value
The I2t rating is related to the amount of energy let through by the fuse element when it clears the electrical fault. This term is normally used in short circuit conditions and the values are used to perform co-ordination studies in electrical networks. I2t parameters are provided by charts in manufacturer data sheets for each fuse family. For coordination of fuse operation with upstream or downstream devices, both melting I2t and clearing I2t are specified. The melting I2t is proportional to the amount of energy required to begin melting the fuse element. The clearing I2t is proportional to the total energy let through by the fuse when clearing a fault. The energy is mainly dependent on current and time for fuses as well as the available fault level and system voltage. Since the I2t rating of the fuse is proportional to the energy it lets through, it is a measure of the thermal damage from the heat and magnetic forces that will be produced by a fault end.

Breaking capacity
The breaking capacity is the maximum current that can safely be interrupted by the fuse. This should be higher than the prospective short-circuit current. Miniature fuses may have an interrupting rating only 10 times their rated current. Fuses for small, low-voltage, usually residential, wiring systems are commonly rated, in North American practice, to interrupt 10,000 amperes. Fuses for commercial or industrial power systems must have higher interrupting ratings, with some low-voltage current-limiting high interrupting fuses rated for 300,000 amperes. Fuses for high-voltage equipment, up to 115,000 volts, are rated by the total apparent power (megavolt-amperes, MVA) of the fault level on the circuit.

Some fuses are designated high rupture capacity (HRC) or high breaking capacity (HBC) and are usually filled with sand or a similar material.

Low-voltage high rupture capacity (HRC) fuses are used in the area of main distribution boards in low-voltage networks where there is a high prospective short circuit current. They are generally larger than screw-type fuses, and have ferrule cap or blade contacts. High rupture capacity fuses may be rated to interrupt current of 120 kA.

HRC fuses are widely used in industrial installations and are also used in the public power grid, e.g. in transformer stations, main distribution boards, or in building junction boxes and as meter fuses.

In some countries, because of the high fault current available where these fuses are used, local regulations may permit only trained personnel to change these fuses. Some varieties of HRC fuse include special handling features.

Rated voltage
The voltage rating of the fuse must be equal to or, greater than, what would become the open-circuit voltage. For example, a glass tube fuse rated at 32 volts would not reliably interrupt current from a voltage source of 120 or 230 V. If a 32 V fuse attempts to interrupt the 120 or 230 V source, an arc may result. Plasma inside the glass tube may continue to conduct current until the current diminishes to the point where the plasma becomes a non-conducting gas. Rated voltage should be higher than the maximum voltage source it would have to disconnect. Connecting fuses in series does not increase the rated voltage of the combination, nor of any one fuse.

Medium-voltage fuses rated for a few thousand volts are never used on low voltage circuits, because of their cost and because they cannot properly clear the circuit when operating at very low voltages.

Voltage drop
The manufacturer may specify the voltage drop across the fuse at rated current. There is a direct relationship between a fuse's cold resistance and its voltage drop value. Once current is applied, resistance and voltage drop of a fuse will constantly grow with the rise of its operating temperature until the fuse finally reaches thermal equilibrium. The voltage drop should be taken into account, particularly when using a fuse in low-voltage applications. Voltage drop often is not significant in more traditional wire type fuses, but can be significant in other technologies such as resettable (PPTC) type fuses.

Temperature derating
Ambient temperature will change a fuse's operational parameters. A fuse rated for 1 A at 25 °C may conduct up to 10% or 20% more current at −40 °C and may open at 80% of its rated value at 100 °C. Operating values will vary with each fuse family and are provided in manufacturer data sheets.

Markings
Most fuses are marked on the body or end caps with markings that indicate their ratings. Surface-mount technology "chip type" fuses feature few or no markings, making identification very difficult.

Similar appearing fuses may have significantly different properties, identified by their markings. Fuse markings will generally convey the following information, either explicitly as text, or else implicit with the approval agency marking for a particular type:
 * Current rating of the fuse.
 * Voltage rating of the fuse.
 * Time-current characteristic; i.e. fuse speed.
 * Approvals by national and international standards agencies.
 * Manufacturer/part number/series.
 * Interrupting rating (breaking capacity)

Packages and materials
Fuses come in a vast array of sizes and styles to serve in many applications, manufactured in standardised package layouts to make them easily interchangeable. Fuse bodies may be made of ceramic, glass, plastic, fiberglass, molded mica laminates, or molded compressed fibre depending on application and voltage class.

Cartridge (ferrule) fuses have a cylindrical body terminated with metal end caps. Some cartridge fuses are manufactured with end caps of different sizes to prevent accidental insertion of the wrong fuse rating in a holder, giving them a bottle shape.

Fuses for low voltage power circuits may have bolted blade or tag terminals which are secured by screws to a fuseholder. Some blade-type terminals are held by spring clips. Blade type fuses often require the use of a special purpose extractor tool to remove them from the fuse holder.

Renewable fuses have replaceable fuse elements, allowing the fuse body and terminals to be reused if not damaged after a fuse operation.

Fuses designed for soldering to a printed circuit board have radial or axial wire leads. Surface mount fuses have solder pads instead of leads.

High-voltage fuses of the expulsion type have fiber or glass-reinforced plastic tubes and an open end, and can have the fuse element replaced.

Semi-enclosed fuses are fuse wire carriers in which the fusible wire itself can be replaced. The exact fusing current is not as well controlled as an enclosed fuse, and it is extremely important to use the correct diameter and material when replacing the fuse wire, and for these reasons these fuses are slowly falling from favour.

These are still used in consumer units in some parts of the world, but are becoming less common. While glass fuses have the advantage of a fuse element visible for inspection purposes, they have a low breaking capacity (interrupting rating), which generally restricts them to applications of 15 A or less at 250 VAC. Ceramic fuses have the advantage of a higher breaking capacity, facilitating their use in circuits with higher current and voltage. Filling a fuse body with sand provides additional cooling of the arc and increases the breaking capacity of the fuse. Medium-voltage fuses may have liquid-filled envelopes to assist in the extinguishing of the arc. Some types of distribution switchgear use fuse links immersed in the oil that fills the equipment.

Fuse packages may include a rejection feature such as a pin, slot, or tab, which prevents interchange of otherwise similar appearing fuses. For example, fuse holders for North American class RK fuses have a pin that prevents installation of similar-appearing class H fuses, which have a much lower breaking capacity and a solid blade terminal that lacks the slot of the RK type.

Dimensions
Fuses can be built with different sized enclosures to prevent interchange of different ratings of fuse. For example, bottle style fuses distinguish between ratings with different cap diameters. Automotive glass fuses were made in different lengths, to prevent high-rated fuses being installed in a circuit intended for a lower rating.

Special features
Glass cartridge and plug fuses allow direct inspection of the fusible element. Other fuses have other indication methods including:
 * Indicating pin or striker pin — extends out of the fuse cap when the element is blown.
 * Indicating disc — a coloured disc (flush mounted in the end cap of the fuse) falls out when the element is blown.
 * Element window — a small window built into the fuse body to provide visual indication of a blown element.
 * External trip indicator — similar function to striker pin, but can be externally attached (using clips) to a compatible fuse.

Some fuses allow a special purpose micro switch or relay unit to be fixed to the fuse body. When the fuse element blows, the indicating pin extends to activate the micro switch or relay, which, in turn, triggers an event.

Some fuses for medium-voltage applications use two or three separate barrels and two or three fuse elements in parallel.

IEC 60269 fuses

The International Electrotechnical Commission publishes standard 60269 for low-voltage power fuses. The standard is in four volumes, which describe general requirements, fuses for industrial and commercial applications, fuses for residential applications, and fuses to protect semiconductor devices. The IEC standard unifies several national standards, thereby improving the interchangeability of fuses in international trade. All fuses of different technologies tested to meet IEC standards will have similar time-current characteristics, which simplifies design and maintenance.

UL 248 fuses (North America)
In the United States and Canada, low-voltage fuses to 1 kV AC rating are made in accordance with Underwriters Laboratories standard UL 248 or the harmonized Canadian Standards Association standard C22.2 No. 248. This standard applies to fuses rated 1 kV or less, AC or DC, and with breaking capacity up to 200 kA. These fuses are intended for installations following Canadian Electrical Code, Part I (CEC), or the National Electrical Code, NFPA 70 (NEC).

The standard ampere ratings for fuses (and circuit breakers) in USA/Canada are considered 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 125, 150, 175, 200, 225, 250, 300, 350, 400, 450, 500, 600, 700, 800, 1000, 1200, 1600, 2000, 2500, 3000, 4000, 5000, and 6000 amperes. Additional standard ampere ratings for fuses are 1, 3, 6, 10, and 601.

UL 248 currently has 19 "parts". UL 248-1 sets the general requirements for fuses, while the latter parts are dedicated to specific fuses sizes (ex: 248-8 for Class J, 248-10 for Class L), or for categories of fuses with unique properties (ex: 248-13 for semiconductor fuses, 248-19 for photovoltaic fuses). The general requirements (248-1) apply except as modified by the supplemental part (240-x). For example, UL 248-19 allows photovoltaic fuses to be rated up to 1500 volts, DC, versus 1000 volts under the general requirements.

IEC and UL nomenclature varies slightly. IEC standards refer to a "fuse" as the assembly of a fusible link and a fuse holder. In North American standards, the fuse is the replaceable portion of the assembly, and a fuse link would be a bare metal element for installation in a fuse.

Automotive fuses

Automotive fuses are used to protect the wiring and electrical equipment for vehicles. There are several different types of automotive fuses and their usage is dependent upon the specific application, voltage, and current demands of the electrical circuit. Automotive fuses can be mounted in fuse blocks, inline fuse holders, or fuse clips. Some automotive fuses are occasionally used in non-automotive electrical applications. Standards for automotive fuses are published by SAE International (formerly known as the Society of Automotive Engineers).

Automotive fuses can be classified into four distinct categories:
 * Blade fuses
 * Glass tube or Bosch type
 * Fusible links
 * Fuse limiters

Most automotive fuses rated at 32 volts are used on circuits rated 24 volts DC and below. Some vehicles use a dual 12/42 V DC electrical system that will require a fuse rated at 58 V DC.

High voltage fuses
Fuses are used on power systems up to 115,000 volts AC. High-voltage fuses are used to protect instrument transformers used for electricity metering, or for small power transformers where the expense of a circuit breaker is not warranted. A circuit breaker at 115 kV may cost up to five times as much as a set of power fuses, so the resulting saving can be tens of thousands of dollars.

In medium-voltage distribution systems, a power fuse may be used to protect a transformer serving 1–3 houses. Pole-mounted distribution transformers are nearly always protected by a fusible cutout, which can have the fuse element replaced using live-line maintenance tools.

Medium-voltage fuses are also used to protect motors, capacitor banks and transformers and may be mounted in metal enclosed switchgear, or (rarely in new designs) on open switchboards.

Expulsion fuses
Large power fuses use fusible elements made of silver, copper or tin to provide stable and predictable performance. High voltage expulsion fuses surround the fusible link with gas-evolving substances, such as boric acid. When the fuse blows, heat from the arc causes the boric acid to evolve large volumes of gases. The associated high pressure (often greater than 100 atmospheres) and cooling gases rapidly quench the resulting arc. The hot gases are then explosively expelled out of the end(s) of the fuse. Such fuses can only be used outdoors.

These type of fuses may have an impact pin to operate a switch mechanism, so that all three phases are interrupted if any one fuse blows.

High-power fuse means that these fuses can interrupt several kiloamperes. Some manufacturers have tested their fuses for up to 63 kA short-circuit current.

Comparison with circuit breakers
Fuses have the advantages of often being less costly and simpler than a circuit breaker for similar ratings. The blown fuse must be replaced with a new device which is less convenient than simply resetting a breaker and therefore likely to discourage people from ignoring faults. On the other hand, replacing a fuse without isolating the circuit first (most building wiring designs do not provide individual isolation switches for each fuse) can be dangerous in itself, particularly if the fault is a short circuit.

In terms of protection response time, fuses tend to isolate faults more quickly (depending on their operating time) than circuit breakers. A fuse can clear a fault within a quarter cycle of the fault current, while a circuit breaker may take around half to one cycle to clear the fault. The response time of a fuse can be as fast as 0.002 seconds, whereas a circuit breaker typically responds in the range of 0.02 to 0.05 seconds.

High rupturing capacity fuses can be rated to safely interrupt up to 300,000 amperes at 600 V AC. Special current-limiting fuses are applied ahead of some molded-case breakers to protect the breakers in low-voltage power circuits with high short-circuit levels.

Current-limiting fuses operate so quickly that they limit the total "let-through" energy that passes into the circuit, helping to protect downstream equipment from damage. These fuses open in less than one cycle of the AC power frequency; circuit breakers cannot match this speed.

Some types of circuit breakers must be maintained on a regular basis to ensure their mechanical operation during an interruption. This is not the case with fuses, which rely on melting processes where no mechanical operation is required for the fuse to operate under fault conditions.

In a multi-phase power circuit, if only one fuse opens, the remaining phases will have higher than normal currents, and unbalanced voltages, with possible damage to motors. Fuses only sense overcurrent, or to a degree, over-temperature, and cannot usually be used independently with protective relaying to provide more advanced protective functions, for example, ground fault detection.

Some manufacturers of medium-voltage distribution fuses combine the overcurrent protection characteristics of the fusible element with the flexibility of relay protection by adding a pyrotechnic device to the fuse operated by external protective relays.

For domestic applications, Miniature circuit breakers (MCB) are widely used as an alternative to fuses. Their rated current depend on the load current of the equipment to be protected and the ambient operational temperature. They are available in the following ratings: 6A, 10A, 16A, 20A, 25A, 32A, 45A, 50A, 63A, 80A, 100A, 125A.

United Kingdom
In the UK, older electrical consumer units (also called fuse boxes) are fitted either with semi-enclosed (rewirable) fuses (BS 3036) or cartridge fuses (BS 1361). (Fuse wire is commonly supplied to consumers as short lengths of 5 A-, 15 A- and 30 A-rated wire wound on a piece of cardboard.) Modern consumer units usually contain miniature circuit breakers (MCBs) instead of fuses, though cartridge fuses are sometimes still used, as in some applications MCBs are prone to nuisance tripping.

Renewable fuses (rewirable or cartridge) allow user replacement, but this can be hazardous as it is easy to put a higher-rated or double fuse element (link or wire) into the holder (overfusing), or simply fitting it with copper wire or even a totally different type of conducting object (coins, hairpins, paper clips, nails, etc.) to the existing carrier. One form of fuse box abuse was to put a penny in the socket, which defeated overcurrent protection and resulted in a dangerous condition. Such tampering will not be visible without full inspection of the fuse. Fuse wire was never used in North America for this reason, although renewable fuses continue to be made for distribution boards.

The Wylex standard consumer unit was very popular in the United Kingdom until the wiring regulations started demanding residual-current devices (RCDs) for sockets that could feasibly supply equipment outside the equipotential zone. The design does not allow for fitting of RCDs or RCBOs. Some Wylex standard models were made with an RCD instead of the main switch, but (for consumer units supplying the entire installation) this is no longer compliant with the wiring regulations as alarm systems should not be RCD-protected. There are two styles of fuse base that can be screwed into these units: one designed for rewirable fusewire carriers and one designed for cartridge fuse carriers. Over the years MCBs have been made for both styles of base. In both cases, higher rated carriers had wider pins, so a carrier couldn't be changed for a higher rated one without also changing the base. Cartridge fuse carriers are also now available for DIN-rail enclosures.

North America
In North America, fuses were used in buildings wired before 1960. These Edison base fuses would screw into a fuse socket similar to Edison-base incandescent lamps. Ratings were 5, 10, 15, 20, 25, and 30 amperes. To prevent installation of fuses with an excessive current rating, later fuse boxes included rejection features in the fuse-holder socket, commonly known as Rejection Base (Type S fuses) which have smaller diameters that vary depending on the rating of the fuse. This means that fuses can only be replaced by the preset (Type S) fuse rating. This is a North American, tri-national standard (UL 4248–11; CAN/CSA-C22.2 NO. 4248.11-07 (R2012); and, NMX-J-009/4248/11-ANCE). Existing Edison fuse boards can easily be converted to only accept Rejection Base (Type S) fuses, by screwing-in a tamper-proof adapter. This adapter screws into the existing Edison fuse holder, and has a smaller diameter threaded hole to accept the designated Type S rated fuse.

Some companies manufacture resettable miniature thermal circuit breakers, which screw into a fuse socket. Some installations use these Edison-base circuit breakers. However, any such breaker sold today does have one flaw. It may be installed in a circuit-breaker box with a door. If so, if the door is closed, the door may hold down the breaker's reset button. While in this state, the breaker is effectively useless: it does not provide any overcurrent protection.

In the 1950s, fuses in new residential or industrial construction for branch circuit protection were superseded by low voltage circuit breakers.

Fuses are widely used for protection of electric motor circuits; for small overloads, the motor protection circuit will open the controlling contactor automatically, and the fuse will only operate for short circuits or extreme overload.

Coordination of fuses in series
Where several fuses are connected in series at the various levels of a power distribution system, it is desirable to blow (clear) only the fuse (or other overcurrent device) electrically closest to the fault. This process is called "coordination" and may require the time-current characteristics of two fuses to be plotted on a common current basis. Fuses are selected so that the minor branch fuse disconnects its circuit well before the supplying, feeder fuse starts to melt. In this way, only the faulty circuit is interrupted with minimal disturbance to other circuits fed by a common supplying fuse.

Where the fuses in a system are of similar types, simple rule-of-thumb ratios between ratings of the fuse closest to the load and the next fuse towards the source can be used.

Resettable fuses
So-called self-resetting fuses use a thermoplastic conductive element known as a polymeric positive temperature coefficient (PPTC) thermistor that impedes the circuit during an overcurrent condition (by increasing device resistance). The PPTC thermistor is self-resetting in that when current is removed, the device will cool and revert to low resistance. These devices are often used in aerospace/nuclear applications where replacement is difficult, or on a computer motherboard so that a shorted mouse or keyboard does not cause motherboard damage.

Thermal fuses

A thermal fuse is often found in consumer equipment such as coffee makers, hair dryers or transformers powering small consumer electronics devices. They contain a fusible, temperature-sensitive composition which holds a spring contact mechanism normally closed. When the surrounding temperature gets too high, the composition melts and allows the spring contact mechanism to break the circuit. The device can be used to prevent a fire in a hair dryer for example, by cutting off the power supply to the heater elements when the air flow is interrupted (e.g., the blower motor stops or the air intake becomes accidentally blocked). Thermal fuses are a 'one shot', non-resettable device which must be replaced once they have been activated (blown).

Cable limiter
A cable limiter is similar to a fuse but is intended only for protection of low voltage power cables. It is used, for example, in networks where multiple cables may be used in parallel. It is not intended to provide overload protection, but instead protects a cable that is exposed to a short circuit. The characteristics of the limiter are matched to the size of cable so that the limiter clears a fault before the cable insulation is damaged.

Unicode symbol
The Unicode character for the fuse's schematic symbol, found in the Miscellaneous Technical block, is (⏛).

title: Fuse (electrical)


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Fuse (explosives)

In an explosive, pyrotechnic device, or military munition, a fuse (or fuze) is the part of the device that initiates function. In common usage, the word fuse is used indiscriminately. However, when being specific (and in particular in a military context), the term fuse describes a simple pyrotechnic initiating device, like the cord on a firecracker whereas the term fuze  is used when referring to a more sophisticated ignition device incorporating mechanical and/or electronic components, such as a proximity fuze for an M107 artillery shell, magnetic or acoustic fuze on a sea mine, spring-loaded grenade fuze,   pencil detonator, or anti-handling device.

History

Documented evidence suggests that the earliest fuses were first used by the Song Chinese between the 10th and 12th centuries. After the Chinese invented gunpowder, they began adapting its explosive properties for use in military technology. By 1044 they were using gunpowder in simple grenades, bombs, and flamethrowers.

The simplest form of fuse is the burning fuse, believed to date back to the 10th century and originating during the medieval Chinese Song dynasty. This simple fuse consisted of lightweight paper filled with loose gunpowder, and served as a means of delaying ignition in fireworks. This simple form of burning fuse can still be found today in many modern fireworks. A version of this simple fuse is called visco fuse, and consists of the burning core coated with wax or lacquer for durability and water resistance. Early fuses for grenades also consist of a wooden plug with a longitudinal hole filled with a slow burning gunpowder mixture inserted into the grenade. Such fuses were in use until the 18th century. The commercial and military version of a burning fuse referred to as safety fuse (invented by William Bickford) is a textile tube filled with combustible material and wrapped to prevent external exposure of the burning core. Safety fuses are used to initiate the detonation of explosives through the use of a blasting cap.

Fuses
Modern day safety fuses are often used in mining and military operations, to provide a time-delay before ignition, and they more often than not are used to initiate an explosive detonator, thereby starting an explosive chain reaction to detonate a larger more stable main charge. Safety fuses are typically colored green or black (military) or fluorescent orange (commercial) to distinguish them from detonating cords such as Primacord, which are brightly colored or transparent.

Usage
Fuses are found in pyrotechnics, model cannons, matchlock firearms, some improvised explosive devices, and many forms of fireworks.

Types

 * A slow match is a very slow-burning fuse consisting of a hemp or cotton rope saturated with an oxidizer such as potassium nitrate. Slow matches are used as a source of fire for manually lighting other devices, such as matchlock guns, or fuses on black powder cannons. Before percussion caps, slow matches were most suitable for use around black-powder weapons because it could be roughly handled without going out, and only presented a small glowing tip instead of a large flame that risked igniting powder supplies nearby.
 * Today's punks (wood splints covered with ground plant pith or dung and then saturated with nitrate) used for lighting consumer fireworks are a type of slow match.
 * A black match is a type of fuse consisting of cotton string coated with a dried slurry of black powder and glue. This acts as a simple pass-fire, and was used to fire ancient cannons. They are used today in fireworks construction.
 * A quick match or piped match is a type of black powder fuse that burns very quickly, some hundreds of feet per second. They consist of black match covered with a loose paper wrap (pipe). When lit, the flame propagates quickly down the paper pipe from the hot gases produced by the burning powder. Quick matches are used in professional fireworks displays to pass fire nearly instantly between devices that must be physically separated while firing simultaneously, such as a finale rack. Devices which should fire in sequence can be branched from a single master fuse, consisting of quick match spliced onto Visco fuses of various length for time delays.
 * A visco fuse has a core of black powder with one or more textile overwraps. The outer layers may be coated with wax or nitrocellulose lacquer for water resistance. These fuses are widely used in modern pyrotechnics because they burn at a uniform rate, with an easily visible external flame. Depending on their outer treatment, visco fuses are water resistant and the better quality can burn reliably underwater once lit, since the black powder core provides both its own fuel and oxidant.
 * A safety fuse consists of a black powder core in a textile tube, covered with asphaltum or other waterproofing agent, and having an outer wrapper of tough textile or plastic. They are made in a standard diameter designed to be crimped into blasting caps. Once ignited, safety fuses will burn underwater, and have no external flame that might ignite methane or other fuels such as might be found in mines or other industrial environments. Safety fuses are manufactured with specified burn times per 30 cm, e.g. 60 seconds, which means that a length of fuse 30 cm long will take 60 seconds to burn. Manufacturers warn that although every effort is made to ensure uniform burn times, safety fuses are subject to variation depending on conditions and should be used with adequate safety measures in place.
 * An electric match (sometimes Igniter Safety Fuse Electric (ISFE)) lights a main fuse or device when activated by an electric current. They typically consist of a pair of wires leading to a thin resistance wire that heats when current is applied. The resistance wire is covered by a bit of pyrotechnic composition that ignites from the wire heating, providing enough fire to reliably ignite the main fuse via a mechanical connection, or the device directly. Estes model rocket motors are lit by a type of electric match. Large fireworks displays are launched with complex timing sequences using a computer that energizes electric matches connected to the individual device fuses.
 * A flying fish fuse (bumblebee) is an unusual type of component for fireworks. It is made like Visco fuse, but contains a metallic spark composition or other effect instead of black powder. Flying fish can thus perform as a main effect instead of just an initiator. For example, simply lighting a short piece of flying fish on the ground makes it fly through the air, seeming to swim in random directions, while emitting sparks and noise. An aerial shell loaded with many such pieces results in a beautiful myriad of pieces flying and sparking high in the air.
 * A spolette is a delay fuse consisting of a hollow wooden dowel or a paper tube rammed full of black powder. A spolette is glued into the wall of a fireworks shell and ignited by the lift charge that launches the shell into the air. The spolette, after a delay that allows the shell to reach its top of trajectory, ignites the shell's main effect(s). The tough wood construction ensures that the fuse burns reliably despite the explosive force and acceleration of the launch.
 * The saucisson was an early form of fuse.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Fuse (explosives)


text:
Wikipedia:Articles for deletion/KassandraHiroshima

This page is an archive of the discussion surrounding the proposed deletion of the pages entitled Kassandra Hiroshima and Kassandra HiroshimA.

This page is kept as an historic record.

The result of the debate was to delete the articles.

Ladies and gentlemen. Presented for your voting pleasure is an individual of eclectic background who garners an incredible two hits on Google, both referring back to his/her own articles on other sites. - Lucky 6.9 21:46, 27 May 2004 (UTC)

 * Wow. Now THAT is messed up.  A "a punk rock gender queer", eh?  Anyone know exactly what that is?  This article is bizarre.  The author keeps using "zie" in place of "she" the whole way through.  Wowwwww.  Delete.  blankfaze | &#9835 21:51, 27 May 2004 (UTC)
 * Oh. I see that "Zie" actually means something now that I've read the Sie and hir article.  blankfaze | &#9835 21:54, 27 May 2004 (UTC)
 * Vanity, delete. --Wyllium 22:22, 2004 May 27 (UTC)
 * Delete. Not enough google hits. Thue 22:18, 27 May 2004 (UTC)
 * Delete. Vanity pieces have no place here. - jredmond 22:20, 27 May 2004 (UTC)
 * Delete, vanity Deus Ex 23:48, 27 May 2004 (UTC)
 * Delete both. No real hits. Niteowlneils 16:31, 30 May 2004 (UTC)
 * Delete. The Land 18:26, 30 May 2004 (UTC)
 * Delete, agree with the reasoning above. Andris 19:58, Jun 1, 2004 (UTC)

This page is now preserved as an archive of the debate and is no longer 'live'. Subsequent comments on the issue or the deletion should be placed on other relevant 'live' pages. Please do not edit this page.


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Young tableau

In mathematics, a Young tableau (plural: tableaux) is a combinatorial object useful in representation theory and Schubert calculus. It provides a convenient way to describe the group representations of the symmetric and general linear groups and to study their properties. Young tableaux were introduced by Alfred Young, a mathematician at Cambridge University, in 1900. They were then applied to the study of the symmetric group by Georg Frobenius in 1903. Their theory was further developed by many mathematicians, including Percy MacMahon, W. V. D. Hodge, G. de B. Robinson, Gian-Carlo Rota, Alain Lascoux, Marcel-Paul Schützenberger and Richard P. Stanley.

Definitions
Note: this article uses the English convention for displaying Young diagrams and tableaux.

Diagrams

A Young diagram (also called a Ferrers diagram, particularly when represented using dots) is a finite collection of boxes, or cells, arranged in left-justified rows, with the row lengths in non-increasing order. Listing the number of boxes in each row gives a partition $λ$ of a non-negative integer $n$, the total number of boxes of the diagram. The Young diagram is said to be of shape $λ$, and it carries the same information as that partition. Containment of one Young diagram in another defines a partial ordering on the set of all partitions, which is in fact a lattice structure, known as Young's lattice. Listing the number of boxes of a Young diagram in each column gives another partition, the conjugate or transpose partition of $λ$; one obtains a Young diagram of that shape by reflecting the original diagram along its main diagonal.

There is almost universal agreement that in labeling boxes of Young diagrams by pairs of integers, the first index selects the row of the diagram, and the second index selects the box within the row. Nevertheless, two distinct conventions exist to display these diagrams, and consequently tableaux: the first places each row below the previous one, the second stacks each row on top of the previous one. Since the former convention is mainly used by Anglophones while the latter is often preferred by Francophones, it is customary to refer to these conventions respectively as the English notation and the French notation; for instance, in his book on symmetric functions, Macdonald advises readers preferring the French convention to "read this book upside down in a mirror" (Macdonald 1979, p. 2). This nomenclature probably started out as jocular. The English notation corresponds to the one universally used for matrices, while the French notation is closer to the convention of Cartesian coordinates; however, French notation differs from that convention by placing the vertical coordinate first. The figure on the right shows, using the English notation, the Young diagram corresponding to the partition (5, 4, 1) of the number 10. The conjugate partition, measuring the column lengths, is (3, 2, 2, 2, 1).

Arm and leg length
In many applications, for example when defining Jack functions, it is convenient to define the arm length aλ(s) of a box s as the number of boxes to the right of s in the diagram λ in English notation. Similarly, the leg length lλ(s) is the number of boxes below s. The hook length of a box s is the number of boxes to the right of s or below s in English notation, including the box s itself; in other words, the hook length is aλ(s) + lλ(s) + 1.

Tableaux

A Young tableau is obtained by filling in the boxes of the Young diagram with symbols taken from some alphabet, which is usually required to be a totally ordered set. Originally that alphabet was a set of indexed variables $x_{1}$, $x_{2}$, $x_{3}$..., but now one usually uses a set of numbers for brevity. In their original application to representations of the symmetric group, Young tableaux have $n$ distinct entries, arbitrarily assigned to boxes of the diagram. A tableau is called standard if the entries in each row and each column are increasing. The number of distinct standard Young tableaux on $n$ entries is given by the involution numbers
 * 1, 1, 2, 4, 10, 26, 76, 232, 764, 2620, 9496, ... .Standard Young Tableaux.png

In other applications, it is natural to allow the same number to appear more than once (or not at all) in a tableau. A tableau is called semistandard, or column strict, if the entries weakly increase along each row and strictly increase down each column. Recording the number of times each number appears in a tableau gives a sequence known as the weight of the tableau. Thus the standard Young tableaux are precisely the semistandard tableaux of weight (1,1,...,1), which requires every integer up to $n$ to occur exactly once.

In a standard Young tableau, the integer $$k$$ is a descent if $$k+1$$ appears in a row strictly below $$k$$. The sum of the descents is called the major index of the tableau.

Variations
There are several variations of this definition: for example, in a row-strict tableau the entries strictly increase along the rows and weakly increase down the columns. Also, tableaux with decreasing entries have been considered, notably, in the theory of plane partitions. There are also generalizations such as domino tableaux or ribbon tableaux, in which several boxes may be grouped together before assigning entries to them.

Skew tableaux

A skew shape is a pair of partitions ($λ$, $μ$) such that the Young diagram of $λ$ contains the Young diagram of $μ$; it is denoted by $λ/μ$. If $λ = (λ_{1}, λ_{2}, ...)$ and $μ = (μ_{1}, μ_{2}, ...)$, then the containment of diagrams means that $μ_{i} ≤ λ_{i}$ for all $i$. The skew diagram of a skew shape $λ/μ$ is the set-theoretic difference of the Young diagrams of $λ$ and $μ$: the set of squares that belong to the diagram of $λ$ but not to that of $μ$. A skew tableau of shape $λ/μ$ is obtained by filling the squares of the corresponding skew diagram; such a tableau is semistandard if entries increase weakly along each row, and increase strictly down each column, and it is standard if moreover all numbers from 1 to the number of squares of the skew diagram occur exactly once. While the map from partitions to their Young diagrams is injective, this is not the case for the map from skew shapes to skew diagrams; therefore the shape of a skew diagram cannot always be determined from the set of filled squares only. Although many properties of skew tableaux only depend on the filled squares, some operations defined on them do require explicit knowledge of $λ$ and $μ$, so it is important that skew tableaux do record this information: two distinct skew tableaux may differ only in their shape, while they occupy the same set of squares, each filled with the same entries. Young tableaux can be identified with skew tableaux in which $A$ is the empty partition (0) (the unique partition of 0).

Any skew semistandard tableau $B$ of shape $μ = (5,3,2,1)$ with positive integer entries gives rise to a sequence of partitions (or Young diagrams), by starting with $A$, and taking for the partition $B$ places further in the sequence the one whose diagram is obtained from that of $μ$ by adding all the boxes that contain a value ≤ $T$ in $μ$; this partition eventually becomes equal to $i$. Any pair of successive shapes in such a sequence is a skew shape whose diagram contains at most one box in each column; such shapes are called horizontal strips. This sequence of partitions completely determines $μ$, and it is in fact possible to define (skew) semistandard tableaux as such sequences, as is done by Macdonald (Macdonald 1979, p. 4). This definition incorporates the partitions $i$ and $T$ in the data comprising the skew tableau.

Overview of applications
Young tableaux have numerous applications in combinatorics, representation theory, and algebraic geometry. Various ways of counting Young tableaux have been explored and lead to the definition of and identities for Schur functions.

Many combinatorial algorithms on tableaux are known, including Schützenberger's jeu de taquin and the Robinson–Schensted–Knuth correspondence. Lascoux and Schützenberger studied an associative product on the set of all semistandard Young tableaux, giving it the structure called the plactic monoid (French: le monoïde plaxique).

In representation theory, standard Young tableaux of size $λ$ describe bases in irreducible representations of the symmetric group on $T$ letters. The standard monomial basis in a finite-dimensional irreducible representation of the general linear group $λ = (5,4,2,1)$ are parametrized by the set of semistandard Young tableaux of a fixed shape over the alphabet {1, 2, ..., $λ$}. This has important consequences for invariant theory, starting from the work of Hodge on the homogeneous coordinate ring of the Grassmannian and further explored by Gian-Carlo Rota with collaborators, de Concini and Procesi, and Eisenbud. The Littlewood–Richardson rule describing (among other things) the decomposition of tensor products of irreducible representations of $AB$ into irreducible components is formulated in terms of certain skew semistandard tableaux.

Applications to algebraic geometry center around Schubert calculus on Grassmannians and flag varieties. Certain important cohomology classes can be represented by Schubert polynomials and described in terms of Young tableaux.

Applications in representation theory
Young diagrams are in one-to-one correspondence with irreducible representations of the symmetric group over the complex numbers. They provide a convenient way of specifying the Young symmetrizers from which the irreducible representations are built. Many facts about a representation can be deduced from the corresponding diagram. Below, we describe two examples: determining the dimension of a representation and restricted representations. In both cases, we will see that some properties of a representation can be determined by using just its diagram. Young tableaux are involved in the use of the symmetric group in quantum chemistry studies of atoms, molecules and solids.

Young diagrams also parametrize the irreducible polynomial representations of the general linear group $BA$ (when they have at most $μ$ nonempty rows), or the irreducible representations of the special linear group $λ/μ$ (when they have at most $GL_{n}$ nonempty rows), or the irreducible complex representations of the special unitary group $GL_{n}$ (again when they have at most $GL_{n}$ nonempty rows). In these cases semistandard tableaux with entries up to $k$ play a central role, rather than standard tableaux; in particular it is the number of those tableaux that determines the dimension of the representation.

Dimension of a representation
The dimension of the irreducible representation $SL_{n}$ of the symmetric group $n − 1$ corresponding to a partition $k$ of $n$ is equal to the number of different standard Young tableaux that can be obtained from the diagram of the representation. This number can be calculated by the hook length formula.

A hook length $SU_{n}$ of a box $n$ in Young diagram $n − 1$ of shape $n$ is the number of boxes that are in the same row to the right of it plus those boxes in the same column below it, plus one (for the box itself). By the hook-length formula, the dimension of an irreducible representation is $\pi_{λ}$ divided by the product of the hook lengths of all boxes in the diagram of the representation:

 * $$\dim\pi_\lambda = \frac{n!}{\prod_{x \in Y(\lambda)} \operatorname{hook}(x)}.$$

The figure on the right shows hook-lengths for all boxes in the diagram of the partition 10 = 5 + 4 + 1. Thus

 * $$\dim\pi_\lambda = \frac{10!}{7\cdot5\cdot 4 \cdot 3\cdot 1\cdot 5\cdot 3\cdot 2\cdot 1\cdot1} = 288.$$

Similarly, the dimension of the irreducible representation $S_{n}$ of $hook(x)$ corresponding to the partition λ of n (with at most r parts) is the number of semistandard Young tableaux of shape λ (containing only the entries from 1 to r), which is given by the hook-length formula:

 * $$\dim W(\lambda) = \prod_{(i,j) \in Y(\lambda)} \frac{r+j-i}{\operatorname{hook}(i,j)},$$

where the index i gives the row and j the column of a box. For instance, for the partition (5,4,1) we get as dimension of the corresponding irreducible representation of $Y(λ)$ (traversing the boxes by rows):

 * $$\dim W(\lambda) = \frac{7\cdot 8\cdot 9\cdot 10\cdot 11\cdot 6\cdot 7\cdot 8\cdot 9\cdot 5}{7\cdot5\cdot 4 \cdot 3\cdot 1\cdot 5\cdot 3\cdot 2\cdot 1\cdot1} = 66 528.$$

Restricted representations
A representation of the symmetric group on $λ$ elements, $n!$ is also a representation of the symmetric group on $W(λ)$ elements, $GL_{r}$. However, an irreducible representation of $GL_{7}$ may not be irreducible for $S_{n}$. Instead, it may be a direct sum of several representations that are irreducible for $n − 1$. These representations are then called the factors of the restricted representation (see also induced representation).

The question of determining this decomposition of the restricted representation of a given irreducible representation of Sn, corresponding to a partition $n$ of $x$, is answered as follows. One forms the set of all Young diagrams that can be obtained from the diagram of shape $λ$ by removing just one box (which must be at the end both of its row and of its column); the restricted representation then decomposes as a direct sum of the irreducible representations of $S_{n−1}$ corresponding to those diagrams, each occurring exactly once in the sum.

title: Young tableau


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Wikipedia:Articles for deletion/A Smith

Cannot be found on either Allmusic.com or Google. Vanity? --Wyllium 21:58, 2004 May 27 (UTC)

title: Wikipedia:Articles for deletion/A Smith


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General admiral

General admiral or Admiral general was first a Dutch then Danish, German, Russian, Portuguese, Spanish and Swedish naval rank. Its historic origin is a title high military or naval dignitaries of early modern Europe sometimes held, for example the (nominal) commander-in-chief of the Dutch Republic's navy (usually the Prince of Orange).

Denmark
In Denmark, the General Admiral (Generaladmiral) was the term for the commander-in-chief of the Dano-Norwegian navy. The rank below the General Admiral was Lieutenant General Admiral (Generaladmiralløjtnant).

Nazi Germany
In the German Kriegsmarine of the Second World War, Generaladmiral was a rank senior to an Admiral, but junior to a Großadmiral. Generaladmiral was a four-star admiral rank, equivalent to a full admiral in the British and American navies. In the traditional German ranking system until World War II, an admiral was equivalent to a British or American vice admiral.

The sleeve insignia for a Generaladmiral was the same as that of a regular admiral, being a thick rank stripe below three regular stripes ( in German naval parlance). Generaladmirals wore a third pip on their shoulder boards to differentiate them from regular admirals. The German Army and Air Force equivalent of Generaladmiral was the rank colonel general (Generaloberst).

In 1943, a directive was issued that should the Oberbefehlshaber der Kriegsmarine ("commander of the navy") hold the rank of Generaladmiral, he would wear the sleeve insignia of a grand admiral, but the shoulder boards of a Generaladmiral.

A similar practice was used in the German Army, allowing colonel generals to wear four pips on the shoulder board when engaged in duties befitting a field marshal.

The rank of Generaladmiral was first given to the future grand admiral Erich Raeder on 20 April 1936.

List
Other holders of the rank were:
 * Conrad Albrecht (1 April 1939)
 * Alfred Saalwächter (1 January 1940)
 * Rolf Carls (19 July 1940)
 * Hermann Boehm (1 April 1941)
 * Karl Witzell (1 April 1941)
 * Otto Schultze (31 August 1942)
 * Wilhelm Marschall (1 February 1943)
 * Otto Schniewind (1 March 1944)
 * Walter Warzecha (1 March 1944)
 * Oskar Kummetz (16 September 1944)
 * Hans-Georg von Friedeburg (1 May 1945)

Notably, Karl Dönitz was promoted to grand admiral without becoming a Generaladmiral first.

Russian Empire
General-admiral (генера́л-адмира́л) was the highest rank of the Imperial Russian Navy as established by the Table of Ranks and equivalent to field marshal. This was purely an honorific rank and for much of its existence, it was awarded only to a person on active duty, usually for the head of the naval department, and typically a descendant of the Romanov royal family.

There were only ten holders of this rank:
 * Count Franz Lefort (1695);
 * Count Fedor Golovin, first Russian chancellor (1700);
 * Count Fyodor Matveyevich Apraksin (1708);
 * Count Andrei Ivanovich Osterman or Heinrich Johann Friedrich Ostermann (1740; dismissed 1741);
 * Prince Mikhail Golitsyn (1756);
 * Grand Duke (Emperor since 1796) Pavel Petrovich (1762);
 * Count Alexei Grigoryevich Orlov (1770);
 * Count Ivan Chernyshyov (1796);
 * Grand Duke Constantine Nikolayevich (1831);
 * Grand Duke Alexei Alexandrovich (1883).

The general admiral rank was abolished with the fall of the Empire and was not revived when rank distinctions were reintroduced during 1935–40. The rank of admiral of the fleet of the Soviet Union can be considered as a modern equivalent.

Kingdom of Spain
Almirante general is a rank in the Spanish Navy that is above an admiral, but subordinate to a captain general.

Kingdom of Portugal
Almirante-general was the highest rank in the Portuguese Navy, from 1808 to 1812 and again, from 1892 to 1910. It was the naval equivalent to the rank of marechal-general ("general field marshal") of the Portuguese Army.

The rank was initially introduced in 1808, to be assigned to the commander-in-chief of the navy. The almirante-general had similar functions to those of the former capitão-general da armada (captain general of the navy) which had been extinguished in 1796 and whose functions passed to the Board of the Admiralty. The rank was only given to Infante Pedro Carlos de Bragança, being extinguished when he died in 1812.

In 1892, the almirante-general rank was reintroduced as a mere ceremonial rank to be held by the King of Portugal in his constitutional function of supreme commander of the navy. As supreme commander of the army, the king also held the ceremonial rank of marechal-general. The last holder of the rank was King Manuel II.

Kingdom of Sweden
Generalamiral is the highest rank of admiral that has existed in the Swedish Navy, created by Charles XI in the name of Admiral General (Amiralgeneral). Gustav III revived the rank in 1780, and the same year issued instructions for the General Admiral, which alone was the King in Council's responsible for naval existence and betterment. The rank has been held by Henrik af Trolle (1780–84), Carl August Ehrensvärd (1792–94), Johan af Puke (1812), Victor von Stedingk (1818) and Rudolf Cederström (1823–28).

In fiction
"Admiral General" Aladeen from The Dictator (2012) is a parody of leaders who appoint themselves grandiose military ranks.

title: General admiral


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Triumf

Triumf may refer to:

 * TRIUMF, Canada's national particle accelerator centre
 * 14959 TRIUMF, a minor planet
 * S-400 Triumf, a Russian anti-aircraft weapon system developed in the 1990s
 * Triumf Riza (1979–2007), Kosovo police officer and member of an elite protection unit
 * CS Triumf Bârca, a Romanian professional football club

title: Triumf


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Mutant Enemy Productions

Mutant Enemy Productions is a production company that was created in 1996 by Joss Whedon to produce Buffy the Vampire Slayer. The company also produced the Buffy spin-off, Angel, and his two short-lived science fiction series, the space Western Firefly and his high-concept Dollhouse, produced by 20th Century Fox Television. Mutant Enemy also produced the internet series Dr. Horrible's Sing-Along Blog and the film The Cabin in the Woods. Mutant Enemy produced the superhero series Agents of S.H.I.E.L.D. along with ABC Studios and Marvel Television. Most recently, Mutant Enemy produced the supernatural fiction series The Nevers for HBO.

Its offices (made out of glass bricks) were on the lot of 20th Century Fox in Los Angeles, previously the home of Chris Carter's Ten Thirteen Productions. According to March 2006's issue of UK magazine The Word, the offices were closed not long after Angel was cancelled.

Productions
The following table lists the production credits of Mutant Enemy.

Name
The name "Mutant Enemy" is taken from the song "And You and I" by progressive rock band Yes, of whom Whedon is a professed fan: "There'll be no mutant enemy/we shall certify/political ends/as sad remains will die." (On the special features of the Buffy DVDs, Whedon also says in an interview that he called his typewriter "mutant enemy".)

Original end-of-credits logo
The company's end-of-credits logo and mascot is an intentionally poorly animated vampire monster cartoon figure crossing the screen from right to left and saying, "Grr. Argh." It was drawn and voiced by Whedon himself. In certain episodes of Buffy the animation was changed:

 * "Becoming, Part Two": He says "Oooh, I need a hug" instead.
 * "Amends": He wears a Santa hat.
 * "Graduation Day, Part Two": He wears a graduation cap—the image used is a reversed logo from the U.S. national college honor society Mortar Board.
 * "Once More, with Feeling": He sings the line in falsetto.
 * "Storyteller": The monster (overdubbed by cast member Adam Busch) sings a line from the episode, "We are as Gods".
 * "Chosen": He turns and pulls a face at the viewer.

The episode "Bargaining, Part One" references the end-of-credits logo. Tara gives Giles a small rubber monster and says "And a monster. Sort of a Sunnydale souvenir, we thought. Grr. Argh." In season seven of Buffy, there is a species of ancient Vampires called "Turok-Han" or Ubervamps. They look like more detailed versions of the Mutant Enemy.

In the canonical Buffy the Vampire Slayer: Season 8 comic books, issue 22 "Swell", on page 10, the slogan for an in-comic fictional product is "Vampy Cat! Grr! Argh! He'll love you to the Santorio Corporation!"

Parodies
At the end of the credits of the animated sketch comedy parody show Robot Chicken, a parody of the Mutant Enemy, Inc. logo appeared with Joss Whedon (guest starring as himself) providing the "Grr... Argh..." As the enemy mutant rips apart the city, the scene cuts to an office where Joss Whedon is playing with dolls and an executive says to him, "Come on Joss, that's why you got kicked off Wonder Woman."

New end-of-credits logo
With The Nevers, the Mutant Enemy vampire end-credits logo was replaced. The new end-of-credits card features a typewriter, upon which the company's name is affixed as an embossed label maker label.

Members
Staff members of Mutant Enemy, all of whom have writing and/or production credits on at least one of the above shows, have included, in alphabetical order:

 * Jeffrey Bell
 * Elizabeth Craft
 * Steven S. DeKnight
 * Ben Edlund
 * Jane Espenson
 * Sarah Fain
 * David Fury
 * Drew Goddard
 * Drew Z. Greenberg
 * David Greenwalt
 * Rebecca Rand Kirshner
 * Tim Minear
 * Jose Molina
 * Marti Noxon
 * Doug Petrie
 * Mere Smith
 * Maurissa Tancharoen
 * Jed Whedon
 * Joss Whedon
 * Zack Whedon

title: Mutant Enemy Productions


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TRIUMF

TRIUMF is Canada's national particle accelerator centre. It is considered Canada's premier physics laboratory, and consistently regarded as one of the world's leading subatomic physics research centres. Owned and operated by a consortium of universities, it is on the south campus of one of its founding members, the University of British Columbia in Vancouver, British Columbia, Canada. It houses the world's largest normal conducting cyclotron, a source of 520 MeV protons, which was named an IEEE Milestone in 2010. Its accelerator-focused activities involve particle physics, nuclear physics, nuclear medicine, materials science, and detector and accelerator development.

Over 500 scientists, engineers, technicians, tradespeople, administrative staff, postdoctoral fellows, and students work at the site. It attracts over 1000 national and international researchers every year, and has generated over $1 billion in economic activity over the last decade.

To develop TRIUMF's research priorities, physicists based at the facility and the university follow the Natural Sciences and Engineering Research Council's (NSERC) long-range plan for subatomic physics. TRIUMF also has over 50 international agreements for collaborative research.

Asteroid 14959 TRIUMF is named in honour of the laboratory.

History
TRIUMF was founded in 1968 by Simon Fraser University, the University of British Columbia, and the University of Victoria to meet research needs that no single university could provide. The name TRIUMF was originally an acronym based on TRI University Meson Facility, but no longer reflects its current state as a consortium of 19 member and associate universities across Canada.

Since its inception as a local university facility, it has evolved into a national laboratory while maintaining strong ties to Canadian universities' research programs. Its related fields of study have expanded from nuclear physics to include particle physics, molecular and materials science, nuclear medicine, and accelerator research and development.

TRIUMF's 520 MeV cyclotron was officially commissioned on February 9, 1976 by Pierre Trudeau, the 15th Prime Minister of Canada, who said, "I don't really know what a cyclotron is, but I am certainly very happy Canada has one."

Before the Riken SRC (superconducting ring cyclotron) was built, TRIUMF was the world's largest cyclotron in terms of weight and beam or magnetic field radius. The Riken SRC is now heavier than the TRIUMF cyclotron, but TRIUMF has the largest beam radius and largest vacuum tank. Riken's magnetic field covers from 3.5 m to 5.5 m radius with maximum beam radius of about 5 m, while TRIUMF's field goes from 0 to about 320 inches radius with maximum beam radius of 310 inches, as it requires a lower magnetic field to reduce EM stripping.

Laboratory directors
TRIUMF has had nine directors of its operations:
 * John Warren – 1968–1971
 * John Reginald Richardson – 1971–1976
 * Jack Sample – 1976–1981
 * Erich Vogt – 1981–1994
 * Alan Astbury – 1994–2001
 * Alan Shotter – 2001–2007
 * Nigel S. Lockyer – 2007–2013
 * Jonathan A. Bagger – 2014–2020
 * Nigel Smith – 2021–present

Historic timeline
1965 – BC nuclear physicists agree on meson facility

1968 – John Warren becomes first director of TRIUMF

1969 – TRIUMF holds opening ceremony

1970 – Ground-breaking ceremony

1971 – Cyclotron assembly begins, Reginald Richardson becomes director of TRIUMF

1974 – Cyclotron produces its first beam

1975 – Proton science program initiated, first polarized proton beam, first μSR experiment at TRIUMF

1976 – Pierre Elliot Trudeau's official dedication, Dr. Erich Vogt becomes an Officer of the Order of Canada, Jack Sample becomes director of TRIUMF

1977 – Medium-resolution spectrometer MRS in operation, first Ph.Ds using TRIUMF beams

1978 – Neutron activation analysis started, AECL/Nordion agreement for medical isotope production, first production of Iodine-123 on Beamline 4A for distribution in Canada

1979 – First new pion/muon beamline M13, pion cancer therapy program initiated

1980 – PET camera construction begins (2nd in Canada), TPC built to study rare decas (1st used in an experiment)

1981 – KAON Factory studies initiated, Erich Vogt becomes director of TRIUMF

1982 – Isotope pipeline to UBC hospital installed, completion of n-p and p-p program, AECL Commercial Products ships first isotopes from TRIUMF

1983 – PET dedicated by the Queen, first commercial cyclotron on site, first isotope separation on-line (ISOL) study

1985 – First purpose-built surface muon channel, NSERC funds HERA beamline at the DESY Lab in Germany

1986 – Contribution to 50 MeV beamline to HERA on behalf of Canada

1987 – Yamasaki awarded Imperial Medal (μSR cited), TISOL facility produces first radioactive beam, University of Manitoba and Université de Montréal become associate members, TRIUMF becomes Canada's national meson facility

1988 – EBCO makes first 30 MeV medical cyclotron, KAON Factory project-definition study funded, University of Toronto becomes an associate member

1989 – NRC adds Tech Transfer to TRIUMF mandate, University of Regina becomes an associate member

1990 – TR-30 installed, ISACI(isotope accelerator) design begins

1991 – Buckyballs studied by μSR, Second arm spectrometer SASP completed

1992 – Rob Kiefl wins Herzberg Medal for MuSR studies, TISOL Red Giant 12C(α,γ)

1993 – Atom trapping begins at TRIUMF, TR-13 medical cyclotron installed

1994 – Alan Astbury becomes director of TRIUMF, ATLAS and LHC involvement at CERN initiated

1995 – Ocular melanoma treatment begins, TRINAT first traps atoms, HERMES detector components to HERA, commercial radiation effect testing with protons begin

1996 – BaBar central wire chamber construction approved

1997 – ISAC-I civil construction begins, TWIST approved, SNO involvement begins, DRAGON experiment proposed

1998 – First beam from ISAC-I, Carleton University and Queens University become associate members, BaBar central wire chamber delivered, NSERC funds DRAGON

1999 – World's highest proton beam current ISOL (isotope online) facility, lifetime measurements of 37-K at ISAC, TRIUMF becomes Canada's National Laboratory for Particle and Nuclear Physics

2000 – Carleton University becomes a full member, McMaster University becomes an associate member, ISAC-II approved, ISAC-I accelerates first stable beam, CSI awarded for new PET, 8π spectrometer moved to TRIUMF

2001 – ISAC first accelerated rare-isotopes, first ISAC-I PRL, TUDA and DRAGON commissioned

2002 – Initial TIGRESS funding, TITAN development begins

2003 – University of Guelph becomes associate member, ISAC-II building opened, LHC magnets delivered to Geneva, Switzerland, ATLAS Tier-1 first CPUs received

2004 – University of Toronto becomes a full member, Saint Mary's University becomes an associate member, Seaborg Award to Don Fleming for pioneering work in muonium, charge radius of 11Li measured, T2K collaboration with J-PARC begins, Synergy Award for collaboration between TRIUMF and Nordion

2005 – 100th patient treated for ocular melanoma, TUDA 21Na(ρ,ρ')21Na results published, Jean-Michel Poutissou awarded Legion of Honour (France), first muon decay results from TWIST experiment

2006 – DRAGON 26Al(ρ,γ)27Si results published

2007 – Université de Montréal becomes a full member, Synergy Award for collaboration between TRIUMF and D-PACE, Nigel Lockyer becomes director of TRIUMF, first ISAC-II experiment 11Li(ρ,t)9Li measurement with MAYA, mass measurement of 11Li (shortest-lived and lightest ion ever measured in Penning trap)

2008 – TUDA measurement of 18F(ρ,α)15O, TRIUMF forms AAPS (Advanced Applied Physics Solutions) with CECR Research and development partnership with VECC Laboratory, Kolkata, India begins, Mass measurement of 6He (lightest ever so measured)

2009 – TIGRESS fully operational, new Nordion/TRIUMF radio-chemistry R&D initiative, TWIST obtains final results on muon decay, M9 beam line upgrade completed

2010 – ARIEL (Advanced Rare IsotopE Laboratory) project begins, first actinide target at ISAC

2011 – TRIUMF sets a world record for isotope production

2015 – A TRIUMF-led multidisciplinary consortium is awarded the NSERC Brockhouse Canada Prize for Interdisciplinary Research in Science and Engineering for their outstanding collaboration in realizing a solution for the safe and reliable production of the critical medical isotope technetium-99m using cyclotrons. The consortium includes physics, chemistry, and nuclear medicine experts from TRIUMF, the BC Cancer Agency, the Centre for Probe Development and Commercialization (CPDC), the Lawson Health Research Institute, and the University of British Columbia

2018 – TRIUMF Celebrates its semicentennial, 50-years of operations, since receiving first funding.

2020 – TRIUMF becomes an incorporated entity. TRIUMF Inc. is a not-for-profit registered charity.

Canadian university partners
TRIUMF is owned and operated as a joint venture by a consortium of 21 universities, including 14 full and 7 associate members. The member universities consist of the University of Alberta, the University of British Columbia, Carleton University, University of Guelph, University of Manitoba, Université de Montréal, Simon Fraser University, Queen's University, University of Toronto, University of Victoria, University of Waterloo and York University. The associate universities consist of the University of Calgary, McMaster University, University of Northern British Columbia, University of Regina, McGill University, Saint Mary's University, Université de Sherbrooke, the University of Winnipeg, and Western University.

Organizational structure
TRIUMF is organized into four divisions that focus on varying aspects of research and operations:

 * The Accelerator Division, responsible for the operation, maintenance, and upgrades required for all of the 520 MeV Cyclotron, ISAC, and TR-13 facilities. It is also responsible for the design, construction and commissioning of future on-site accelerators, and provides support for external accelerator projects.
 * The Engineering Division, responsible for the engineering, design and fabrication of mechanical, structural and electronic components, and for electrical and mechanical services and site maintenance.
 * The Physical Sciences Division, responsible for scheduling experiments approved by the Experimental Evaluation Committee (EEC), and for the design, installation, operation and maintenance of components, systems and subsystems for all experimental operations at the site. It is also responsible for the coordination of infrastructure support for external programs.
 * The Life Sciences Division, responsible for the support of projects approved by the Life Science Projects Evaluation Committee (LSPEC), and provides support for collaborations with the Pacific Parkinson's Research Centre (PPRC), BC Cancer (BCC), BWXT and other university faculties relying on radio-tracers from TRIUMF for their research. It is also responsible for the design, installation, operation and maintenance of components, systems and subsystems for the radioisotope production and processing facilities for tracers to be used in research projects both at TRIUMF and other laboratories. TRIUMF's nuclear medicine department is part of this division.

The Office of the Director, supported by the Deputy Directors of Research and Operations, has general oversight for:

 * The facility's administrative departments, including accounting and finance, environmental health and safety, general administration and security, human resources, procurement, quality assurance, strategic planning, communications and outreach, and supply chain management
 * The Applied Technology Group, consisting of several work teams including Isotope production, cyclotron operations, and technical support, which focuses on the production of radioactive isotopes for use by the medical isotope division of BWX Technologies (formerly Nordion), which are ultimately deployed in the development of drugs and diagnosis and treatment of disease.

Additionally, TRIUMF Innovations (link to website) is TRIUMF's commercialization arm, linking its laboratories activities with tangible business and commercialization opportunities. Established in 2017, it replaced Advanced Applied Physics Solutions, Inc. (AAPS), TRIUMF's previous commercialization entity.

Experiments
As TRIUMF has selectively applied its expertise to other areas of research, and to the generation of entrepreneurial opportunities, its core program of nuclear, particle and accelerator physics has expanded to cover key areas in life, molecular and materials sciences.

Main cyclotron and proton beam lines
At the heart of TRIUMF is the 520 MeV cyclotron that produces the primary proton beams. A large fraction of the TRIUMF program relies on these beams, including the ISAC, the Centre for Molecular and Materials Science programs in μSR and β-NMR, and the Proton Treatment Facility. The operation of the main cyclotron has enabled TRIUMF to acquire the expertise to operate the three medical cyclotrons for BWXT Medical and the TR-13 medical cyclotron used to produce medical isotopes, and assist companies to exploit commercial opportunities for the sale of cyclotron and other accelerator technologies.

The 520 MeV cyclotron
TRIUMF produces negatively charged hydrogen ions (H−: 1 proton, 2 electrons) from an ion source. The ions are transported through an evacuated electrostatic beam line containing elements to focus and steer the beam over 60m to the cyclotron. The 520 MeV (million electron volts) variable energy cyclotron accelerates these ions with a high frequency alternating electric field and uses a massive six-sector magnet to confine the beam in an outward spiral trajectory. Inserting a very thin graphite extraction foil strips, or removes, the electrons from the H− ion while allowing the proton to pass through. The proton, because it is a positively charged particle, is deflected in the outward direction due to the magnetic field and is directed to a proton beam line.

The accelerating process takes approximately 0.3 ms before the proton achieves three-quarters the speed of light. The success of TRIUMF's programs depends on the ability to deliver protons from the cyclotron reliably. Typically, the cyclotron, although over 35 years old, averages an up-time of greater than 90% (2000–2007), with the 15-year average just under 90%. Typically the beam is delivered for about 5,000 hours per year with one major (three month) and one minor (one month) maintenance periods. The cyclotron beam properties and capabilities have improved over the years as a result of systems upgrades and the fundamental infrastructure providing the magnetic and electrical fields and the RF resonators as well as the vacuum vessel will serve TRIUMF for many more years.

The Four Proton Beamlines
TRIUMF has four independent extraction probes with various sizes of foils to provide protons simultaneously to up to four beam lines. Because of the high energy of the proton beam, these beamlines use magnetic rather than electrostatic focusing and steering elements.

 * Beamline 1A (BL1A) : can deliver 180 to 500 MeV protons to two target systems. The beam power ranges from 50 to 75 kW. The first target, T1, services three experimental channels. The second target, T2, services two μSR experimental channels. Downstream of T2 is a 500 MeV facility used to produce strontium isotopes for medical-imaging generators as well as the Thermal Neutron Facility (TNF).

 * Beamline 1B : separates off BL1 at the edge of the cyclotron vault and provides international users with the Proton Irradiation Facility (PIF) that is used for radiation testing of electronic circuits, for example, mimicking space radiation for testing computer chips.

 * Beamline 1U (BL1U) : shares the proton beam with beamline 1A and is designed to divert up to 20 kW of its beam power onto a spallation source for ultracold neutrons, which can be used to study fundamental properties of the neutron.

 * Beamline 2A (BL2A) : capable of providing 475 to 500 MeV proton beams at up to 50 kW to the ISAC target facility that produces rare-isotope ion beams for a host of Canadian and international experiments.

 * Beamline 2C (BL2C) : used for the Proton Therapy Program to treat choroidal melanomas (eye tumours) and proton irradiation to produce strontium isotopes, which are chemically processed and then used for medical imaging generators. This beam line also has the flexibility to provide protons of lower energy for PIF users. The energy range for this line is 70 to 120 MeV.

 * Beamline 4 North (BL4N) : (expected completion 2017), will be a new 500 MeV beamline used for the proposed expansion of ISAC with a specialized actinide target.

ISAC and ARIEL facilities for rare-isotope beams
The ISAC and ARIEL (under construction) facilities produces and uses heavy ion beams to produce short-lived isotopes for study. Proton beam from the main accelerator is used as a driver beam at ISAC via beamline BL2A and one of the two ARIEL target stations via beamline BL4N (under construction) to produce beams of exotic isotopes which are further accelerated using linear accelerators. The second target station at ARIEL uses an electron beam from the TRIUMF elinac as a driver beam. Several experiments study the properties and structure of these exotic isotopes along with their nucleosynthesis. Between ISAC-I and ISAC-II, many experiments can be completed.

ISAC-I facility
In the ISAC-I facility, 500 MeV protons at up to 100 μA can be steered onto one of two production targets to produce radioactive isotopes. The isotopes pass through a heated tube to a source where they are ionized, accelerated off the source's high-voltage platform at up to 60 kV and sent through a mass separator to select the ion beam of choice. The beam is transported in the low-energy beam transport (LEBT) electrostatic beam line and sent via a switch-yard to either the low-energy experimental area or to a series of room-temperature accelerating structures to the ISAC-I medium-energy experimental area. Experiments at ISAC-I include:

8π spectrometer
A microscope used to examine the behaviour of atomic nuclear produced, which are collected at the centre of 8pi where they undergo radioactive decay. The main component of the 8π spectrometer are the Hyper-pure Germanium detectors used to observe gamma rays emitted from excited states of daughter nuclei.

DRAGON
The Detector of Recoils And Gammas Of Nuclear Reactions (DRAGON) is an apparatus designed to measure the rates of nuclear reactions important in astrophysics, particularly nucleosynthesis reactions which occur in the explosives environments of nova, supernova, and x-ray bursters.

Laser spectroscopy
The Collinear Fast-Beam Laser Spectroscopy (CFBS) experiment at TRIUMF is designed to exploit the high beam-intensity and radioisotope-production capability of TRIUMF's ISAC facility, as well as modern ion-trap beam-cooling techniques, in order to measure the hyperfine energy levels and isotope shifts of short-lived isotopes using laser spectroscopy.

TITAN
TRIUMF's Ion Trap for Atomic and Nuclear Science (TITAN) measures the mass of short-lived isotopes with high precision. Radioactive isotopes from ISAC are sent to TITAN to undergo cooling, charge-breeding and trapping. The entire process occurs in about 10 milliseconds, allowing radioactive isotopes with short half lives to be studied.

TRINAT
TRINAT, TRIUMF's Neutral Atom Trap, holds a cluster of neutral atoms suspended in a very small space, in high vacuum, allowing for the study of decay products of radioactive atoms.

ISAC-II facility
The rare-isotope beams produced in the ISAC-II facility are transported in the low-energy beam transport (LEBT) electrostatic beam line and sent via a switch-yard to either the low-energy experimental area or to a series of room-temperature accelerating structures in the ISAC-I medium-energy experimental area. For high-energy delivery, the drift tube linac (DTL) beam is deflected north along an S-bend transfer line to the ISAC-II superconducting linear accelerator (SC-linac) for acceleration above the Coulomb barrier (5–11 MeV/u). TRIUMF began developing superconducting accelerator technology in 2001 and is now a leader in the field with a demonstrated accelerating gradient (at low beta) significantly above other operating facilities. Experiments at ISAC-II include:

EMMA
The ElectroMagnetic Mass Analyzer (EMMA) (completion date 2016) is a recoil mass spectrometer for TRIUMF's ISAC-II facility. ISAC-II will provide intense beams of radioactive ions with masses up to 150 atomic mass units to international scientists studying nuclear structure and nuclear astrophysics. The energies of these beams will depend on the specific nuclei being accelerated, but typical top speeds will range from 10–20% of the speed of light.

HERACLES
Formerly known as the Chalk River/Laval array, HERACLES consists of 150 scintillators detectors covering almost 4-pi. It was used in over a dozen of experiments in the last ten years for multi-fragmentation studies at intermediate energies (10 to 100 MeV/A).

TIGRESS
The TRIUMF-ISAC Gamma-Ray Escape Suppressed Spectrometer (TIGRESS) is a state-of-the art new gamma-ray spectrometer designed for a broad program of nuclear physics research with the accelerated radioactive ion beams provided by the ISAC-II superconducting linear accelerator.

ISAC-I/II
The experiments listed below utilize both facilities.

TUDA
A general purpose facility for studying nuclear reactions of astrophysical significance with solid state detectors.

TACTIC
An ionization chamber with full track reconstruction capabilities for studying reactions of astrophysical importance.

DSL
TRIUMF's Doppler Shift Lifetimes facility, which is an experimental setup for the measurement of the lifetimes of excited states of nuclei.

ATLAS Canadian Tier-1 Data Centre
The ATLAS experiment at the Large Hadron Collider (LHC) at CERN uses proton-proton collisions at the highest energy ever achieved in the laboratory to look for the Higgs Boson, the particle central to the current model of how subatomic particles attain mass. ATLAS will also search for phenomena "beyond the standard model" of particle physics such as supersymmetry, extra dimensions, and quark compositeness. The ATLAS detector will observe the particles emerging from the roughly 900 million proton-proton collisions per second and, although fast electronics will filter the events so that only those most likely to be of interest will be recorded, ATLAS will produce 3.5–5.0 petabytes of data per year (one petabyte is one million gigabytes). In addition, secondary data sets will be produced that could double the amount of data produced.

In order to analyze this enormous amount of information, CERN is coordinating an international network of large high-performance computing centres that are linked by grid computing tools so that they act as one huge system. This network is called the Worldwide LHC Computing Grid (WLCG). The Canadian Tier-1 Data Centre, located at TRIUMF, works with nine of the other ATLAS Tier-1 centres in the world to process the raw data produced by the experiment. In addition, Tier-2 centres located in universities, both in Canada and abroad, are used to further process the results of the Tier-1 analysis and extract groundbreaking physics results from the data. The Tier-2 centres will also be the primary sites for computer simulations of ATLAS, which is an integral part of the data analysis.

Centre for Molecular and Materials Science
TRIUMF uses subatomic particles as probes of materials structure at the Centre for Molecular and Materials Science (CMMS). The chief techniques are μSR and β-NMR.

μSR
TRIUMF utilizes a technique called μSR, a powerful probe into materials like semiconductors, magnets and superconductors. Beams of positive muons are created with their spins lined up in the same direction. When these beams are shot into a material, the muons' spins precess (wobble like a top) around the local magnetic fields in the material. The unstable muons soon decay into positrons; since these antielectrons tend to be emitted in the direction of the muons' spin, μSR scientists can examine how the internal magnetic fields of different materials have affected the muons' spins by observing the directions in which the positrons are emitted.

β-NMR
β detected NMR is an exotic form of nuclear magnetic resonance (NMR) in which the nuclear spin precession signal is detected through the beta decay of a radioactive nucleus. The central question to be studied is how the local electronic and magnetic properties near an interface or surface of new materials (e.g.,. a high Tc superconductor) differ from those of the bulk.

Detector development
TRIUMF uses its expertise gained from the development of detectors for particle and nuclear physics, in collaboration with Canadian universities, to support advanced detector development, including for molecular and materials sciences and nuclear medicine. TRIUMF's Science and Technology Department designs and constructs complete detector systems including mechanics, services, front end electronics, digital signal processing and data acquisition.

Nuclear medicine laboratories
The core of the TRIUMF nuclear medicine program is Positron Emission Tomography or PET imaging, a technique whereby tiny amounts of radioactive nuclei known as radioisotopes are combined with certain bio-molecules and injected into the body. The biomolecules can be "traced" by imaging the decay products (two photons produced by the decay of the radioactive nucleus via the emission of a positron) outside the body. PET allows the concentration of positron-labeled compounds to be determined quantitatively in space and time within the living body. PET is more sensitive than any other human imaging method, such as MRI or CT, especially for the detection of cancer.

The PET program facilities at TRIUMF include cyclotron systems for the production of radioisotopes, chemistry labs for the synthesis of radiopharmaceuticals and quality control labs. TRIUMF currently uses the TR-13 medical cyclotron and target systems for the production of 18F, 11C, and 13N. Radiopharmaceutical production facilities include the small modular clean room at the cyclotron for the synthesis of 18F-fluorodeoxyglucose (FDG). for BCCA as well as three chemistry annex labs for production and development of radiopharmaceuticals used in brain research and other programs at UBC.

Pacific Parkinson's Research Centre (PPRC) is a joint TRIUMF/UBC program studying central nervous system disorders. Approximately 80% of the studies are related to Parkinson's disease, and the remainder are related to mood disorders and Alzheimer's disease. The program has explored the origins, progression, and therapies of the disease as well as the complications arising from therapy using molecular imaging as the primary tool.

The Functional Imaging Program at the BCCA is a collaboration among the agency, TRIUMF, UBC, and the BC Children's Hospital. Capital acquired through the BC Provincial Health Services Authority Emerging Technologies Fund allowed purchase of the province's first hybrid PET/CT scanner in 2004. The clinical PET/CT program, located at BCCA's Vancouver Centre, was enabled by TRIUMF supplying 18F, the positron emitting radionuclide used in production of 18F-fluorodeoxyglucose (FDG). FDG, as a marker of glucose metabolism, is the tracer used in oncologic PET imaging, a diagnostic study which has become a standard of care in the management of many cancer types.

Proton and neutron irradiation facilities
Beginning in 1995, TRIUMF has built up several beamlines that provide low-intensity, energetic proton and neutron beams to simulate radiation exposures either in space or terrestrial environments. Even at low intensity, several minutes of exposure in these beams can correspond to years of operation in space, air, or ground so that accelerated testing of electronics can be carried out.

These TRIUMF facilities, PIF & NIF, have since become recognized as premier test sites for space-radiation effects using protons and, with the capability of using these protons to produce a neutron-energy spectrum similar to that found at aircraft altitudes and at ground level, testing with neutrons is also possible. A large fraction of the proton users are Canadian space-related companies such as MDA Corporation, while neutron use is primarily by international companies for avionics, microelectronics and communications equipment, such as The Boeing Company or Cisco Systems, Inc.

Additionally, one of the beamlines was used for the cancer treatment of ocular melanoma at the Proton Therapy Centre which was operated in conjunction with the BC Cancer Agency and the UBC Department of Ophthalmology. Before proton treatment became available, the most common course of action was removal of the eye. Other possible treatments included surgical removal of the tumour (which has severe limitations), or implanting a radioactive disk on the wall of the eye under the tumour for some days. These alternatives were unsuitable for large tumours, and could damage sensitive parts of the eye, often resulting in loss of vision. After proton therapy, however, patients can retain useful vision. The protons enter the eye at a carefully controlled energy, and come to rest at a precise, predictable distance inside. They deposit their energy of motion (kinetic energy) in a very narrow layer, destroying living cells in that layer. Because the beam of protons is so concentrated and deposits its energy so predictably, we can successfully destroy a tumour while better preserving the other nearby parts of the eye. The proton therapy program at TRIUMF was discontinued in 2019.

External scientific collaborations
TRIUMF is also involved in the development and construction of detectors and equipment for larger particle physics experiments located all over the world.

ALPHA
The international ALPHA Collaboration, focused on trapping antihydrogen with experiments based at CERN, includes members from TRIUMF. The ALPHA-Canada team, led by TRIUMF research scientist Dr. Makoto C. Fujiwara, was recognized with the 2013 NSERC John C. Polanyi Award for their work with the ALPHA team at CERN in understanding antimatter. The Canadian team included over a dozen scientists and students working in plasma, atomic, condensed matter, particle, detector, and accelerator physics, from the University of British Columbia (UBC), Simon Fraser University (SFU), the University of Calgary, York University, and TRIUMF.

KEK
TRIUMF has a longstanding collaborative relationship with Japan's KEK, which was further enhanced in December, 2015 when it was announced that each organization would be establishing branch offices at the other's respective institution to facilitate the advancement of their physics research activities.

Large Hadron Collider
TRIUMF accelerator physicists, engineers, and technical personnel have unique expertise for the design and construction of critical parts of the accelerator, such as assembling the liquid argon end cap calorimeters for the ATLAS detector. As well, TRIUMF was involved in the construction and procurement of several magnets and power supplies for the LHC itself. The resulting accelerator contributions were a necessary part of the Canadian investment in the project. TRIUMF is also home to the ATLAS-Canada Tier-1 Data Centre, funded by the Canada Foundation for Innovation. This centre will pre-process the raw data from the experiment prior to analysis by Canadian and foreign researchers. It will also provide domestic detector experts access to raw data for detailed calibration and monitoring.

SNO
TRIUMF first became actively involved in the Sudbury Neutrino Observatory (SNO) when the project needed engineering help. TRIUMF's Design Office and Machine Shop built key components of the detector. Moreover, TRIUMF scientists were involved in the project which was honored with the 2015 Nobel Prize in Physics and the 2016 Fundamental Physics Prize for the discovery of neutrino oscillation.

SNOLAB
TRIUMF is involved with a number of projects at SNOLAB. Notable examples include the Helium and Lead Observatory (HALO) supernova neutrino detector which is part of the SuperNova Early Warning System (SNEWS) and Dark Matter Experiment using Argon Pulse-shape discrimination (DEAP) the most sensitive weakly interacting massive particle (WIMP) detector to date.

T2K
TRIUMF is part of the T2K (Tokai-to-Kamioka) neutrino oscillation experiment in Japan. TRIUMF is involved in constructing a time projection chamber and fine-grained detectors composed of plastic scintillators for the T2K near detector, to measure the properties of the neutrino beam at its production site in Tokai before it travels 295 km to Kamioka, over which distance neutrino oscillations are expected to take place.

TRIUMF Users' Group
The TRIUMF Users Group (TUG) is an international community of scientists and engineers with a special interest in the use of the TRIUMF facility. Its purpose is: Any qualified scientist can join the users group. The group's interests are looked after by an elected committee (TRIUMF Users' Executive Committee or TUEC). Part of TUEC's responsibilities is to organize meetings on behalf of the membership were necessary. At least one meeting, the annual general meeting (AGM), is held each year near the beginning of December. A link to the TUG website is listed in the external links below.
 * to provide a formal means for exchange of information relating to the development and use of the facility;
 * to advise members of the entire TRIUMF organization of projects and facilities available;
 * to provide an entity responsive to the representations of its members for offering advice and counsel to the TRIUMF management on operating policy and facilities.

title: TRIUMF


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Spinneret

A spinneret is a silk-spinning organ of a spider or the larva of an insect. Some adult insects also have spinnerets, such as those borne on the forelegs of Embioptera. Spinnerets are usually on the underside of a spider's opisthosoma, and are typically segmented. While most spiders have six spinnerets, some have two, four, or eight. They can move both independently and in concert.

Most spinnerets are not simple structures with a single orifice producing a single thread, but complex structures of many microscopic spigots, each producing one filament. This produces the necessary orientation of the protein molecules, without which the silk would be weak and useless. Spigots can be singular or found in groups, which also permits spiders to combine multiple filaments in different ways to produce many kinds of silk for various purposes. Spinneret morphology can help arachnologists identify the taxon of a specimen and the specific morphology of a spigot can determine its use as well. For example, flagelliform spigot is unique to Araneoidea, and another kind of spigot found in sets of three, referred to as cylindrical gland spots, are found only in females and used for making egg sacs. The desert grass spider, Agelenopsis aperta, has especially prominent spinnerets that extend out of the end of their abdomen.

Various species of spiders use silk extruded from spinnerets to build webs, to transfer sperm, to entrap insects by wrapping it around them, to make egg-cases, to manipulate static electricity in the air, and to fly (ballooning), etc.

Some insect larvae (including silkworms) extrude silk to make a protective cocoon for their metamorphosis. The insects known as web spinners weave silken galleries for protection from predators and the elements while foraging and breeding.

Evolution
Observations suggesting that there might be silk-producing organs on the feet of the zebra tarantula (Aphonopelma seemanni) led to questions about the origins of spinnerets. It was hypothesised that spinnerets in spiders were originally used as climbing aids on the feet and evolved and were used for webmaking at a later time.

title: Spinneret