Collision (telecommunications)

A collision is the situation that occurs when two or more demands are made simultaneously on equipment that can handle only one at any given instant. It may refer to:

References

Collision (Heroes)

"Collision" is the fourth episode of the first season of the NBC science fiction drama series Heroes. It was originally titled "Come Together".

Plot

Matt Parkman is a prisoner of Mr. Bennet and the mysterious man. When it is revealed Matt knows of a Claire, the mysterious man is ordered to "clean Matt out", a painful process.

Hiro and Ando arrive in Las Vegas. Ando helps Hiro with the warning messages for Isaac Mendez, so Isaac will know that he and the city of New York are in danger.

They pass by Niki Sanders and her son Micah, who are on their way to meet Mr. Linderman. Instead, they meet one of his associates. With Micah in the other room, Niki is told she will sexually blackmail a politician Linderman is involved with, as a form of 'insurance'.

Claire Bennet's body lies on the autopsy table as the coroner does a V-incision on her chest. Recording the details, the coroner notes that she was found naked and dragged into the Red River Creek. With the coroner distracted by a phone call, Claire heals up sufficiently to steal a lab coat and sneak out.

Collision (TV series)

Collision is a five-part television drama miniseries, which debuted on ITV & UTV in November 2009. In the same month, it was also on PBS as a series in two parts. It tells the story of a group of strangers whose lives intertwine following a devastating car crash. The crash opens a number of startling revelations as stories of everything from government cover-ups and smuggling, to embezzlement and murder start to unravel.

The series is open-ended, with a number of unresolved issues; moreover, the story is ostensibly resolved in a metafictional manner with a flashback to an incident in the service station and the swatting of a wasp, which precipitates the initial crash, thus allowing the characters to carry on on their journeys. The wasp as a motif and theme is frequently in evidence throughout the series.

The original British broadcast of Collision was edited from the original 5 hours (shown in five parts) down to three and a half hours (210 minutes, shown in two parts). The American broadcast on PBS's Masterpiece Contemporary, the Australian broadcast on ABC1 and the Region 1 (America and Canada) DVD release all featured the shortened version. In Australia, Foxtel and Austar's W Channel aired Collision in its original format of five 45-minute episodes (excluding advertisements), Tuesday, 15 March 2011.

Particle (ecology)

In marine and freshwater ecology, a particle is a small object. Particles can remain in suspension in the ocean or freshwater. However, they eventually settle (rate determined by Stokes' law) and accumulate as sediment. Some can enter the atmosphere through wave action where they can act as cloud condensation nuclei (CCN). Many organisms filter particles out of the water with unique filtration mechanisms (filter feeders). Particles are often associated with high loads of toxins which attach to the surface. As these toxins are passed up the food chain they accumulate in fatty tissue and become increasingly concentrated in predators (see bioaccumulation). Very little is known about the dynamics of particles, especially when they are re-suspended by dredging. They can remain floating in the water and drift over long distances. The decomposition of some particles by bacteria consumes a lot of oxygen and can cause the water to become hypoxic.

Particle analysis

Particle levels in water (or air) can be measured with a turbidity meter and analyzed with a particle counter. They can also be scanned with an underwater microscope, such as ecoSCOPE. Collected particles of size 20 - 200 micrometers hovering in the free water in the vicinity of a harbor had the following contaminant levels (table). Many of those contaminants are carcinogenic.

Grammatical particle

In grammar the term particle has two different meanings.

Traditional meaning

A particle is a part of speech which cannot be inflected, that is it can be neither declined nor conjugated. Particles are the adverb, the preposition, the conjunction and the interjection.

Modern meaning

In modern grammar, a particle is a function word that must be associated with another word or phrase to impart meaning, i.e., does not have its own lexical definition. On this definition, particles are a separate part of speech and are distinct from other classes of function words, such as articles, prepositions, conjunctions and adverbs.

Particles are typically words that encode grammatical categories (such as negation, mood, tense, or case), clitics, or fillers or (oral) discourse markers such as well, um, etc.

Particles are never inflected.

Languages vary widely in how much they use particles, some using them extensively and others more commonly using alternative devices such as prefixes/suffixes, inflection, auxiliary verbs and word order.

Beta particle

A beta particle, sometimes called beta ray, denoted by the lower-case Greek letter beta (β), is a high-energy, high-speed electron or positron emitted in the radioactive decay of an atomic nucleus, such as a potassium-40 nucleus, in the process of beta decay. Two forms of beta decay, β⁻ and β⁺, respectively produce electrons and positrons. Beta particles are a type of ionizing radiation.

β⁻ decay (electron emission)

An unstable atomic nucleus with an excess of neutrons may undergo β⁻ decay, where a neutron is converted into a proton, an electron, and an electron antineutrino (the antiparticle of the neutrino):

This process is mediated by the weak interaction. The neutron turns into a proton through the emission of a virtual W⁻ boson. At the quark level, W⁻ emission turns a down quark into an up quark, turning a neutron (one up quark and two down quarks) into a proton (two up quarks and one down quark). The virtual W⁻ boson then decays into an electron and an antineutrino.

Beta decay commonly occurs among the neutron-rich fission byproducts produced in nuclear reactors. Free neutrons also decay via this process. Both of these processes contribute to the copious numbers of beta rays and electron antineutrinos produced by fission-reactor fuel rods.