Group items tagged

SIP Communicator - the Java VoIP and Instant Messaging client.

SIP Communicator is an audio/video Internet phone and instant messenger that supports some of the most popular VoIP and instant messaging protocols such as SIP, Jabber, AIM/ICQ, MSN, Yahoo! Messenger, Bonjour, IRC and a whole lot of other useful features.

SIP Communicator is completely Open Source / Free Software, and is freely available under the terms of the GNU Lesser General Public License.

Weber (unit) From Wikipedia, the free encyclopedia Jump to: navigation, search In physics, the weber (symbol: Wb;  /ˈveɪbər/, /ˈwɛbər/, or /ˈwiːbər/) is the SI unit of magnetic flux. A flux density of one Wb/m2 (one weber per square meter) is one tesla. The weber is named for the German physicist Wilhelm Eduard Weber (1804–1891). [edit] Definition

The weber may be defined in terms of Faraday's law, which relates a changing magnetic flux through a loop to the electric field around the loop. A change in flux of one weber per second will induce an electromotive force of one volt (produce an electric potential difference of one volt across two open-circuited terminals). Officially,

Weber (unit of magnetic flux) — The weber is the magnetic flux which, linking a circuit of one turn, would produce in it an electromotive force of 1 volt if it were reduced to zero at a uniform rate in 1 second.[1]

Metre From Wikipedia, the free encyclopedia   (Redirected from Meter) Jump to: navigation, search This article is about the unit of length. For other uses of "metre" or "meter", see meter (disambiguation). 1 metre = SI units 100 cm 1000 mm US customary / Imperial units 3.2808 ft 39.370 in The metre (meter in the US), symbol m, is the base unit of length in the International System of Units (SI). Originally intended to be one ten-millionth of the distance from the Earth's equator to the North Pole (at sea level), its definition has been periodically refined to reflect growing knowledge of metrology. Since 1983, it has been defined as "the length of the path travelled by light in vacuum during a time interval of 1 ⁄ 299,792,458 of a second.[1]

A particle carrying a charge of 1 coulomb and passing through a magnetic field of 1 tesla at a speed of 1 meter per second perpendicular to said field experiences a force of 1 newton, according to the Lorentz force law. As an SI derived unit, the tesla can also be expressed as (in SI base units).[3] Units used: A = ampere C = coulomb kg = kilogram m = meter N = newton s = second T = tesla V = volt Wb = weber [edit] Electric vs Magnetic Field

The difference between magnetic field strength (in tesla) vs electric field strength can be confusing.[citation needed] The difference is that a force of magnetic field on a charged particle is generally due to the charged particle's movement[4] while the force imparted by an electric field on a charged particle is not due to the charged particle's movement. This can be seen by looking at the units for each. Electric field is N/C, while magnetic field (in tesla) can be written as N/(C*m/s). The difference between the two is m/s, or velocity. This can further be seen by noting that whether a field is magnetic or electric is dependent on one's relativistic reference frame (that is: one's velocity relative to the field).[5][6] In ferromagnets the movement creating the magnetic field is the electron spin[7] (and to a lesser extent electron orbital angular momentum). In current carrying wire (electromagnets) the movement is due to electrons moving through the wire (whether the wire's straight or circular).

Pourquoi nous ne vendons pas de pub

À nous deux, Brian et moi avons passé 20 ans chez Yahoo, travaillant dur au bon fonctionnement du site. Et aussi oui, travaillant dur à vendre de la pub, parce que c’était ce que Yahoo faisait : recueillir des données, la publication de pages et la vendre de la publicité.

Nous avons été témoins du déclin de Yahoo tandis que continuaient à grandir la taille et l’audience de Google, vendeur d’espaces publicitaires plus efficace et plus rentable. Google savait ce que les utilisateurs recherchaient, pouvant ainsi recueillir plus efficacement des données sur ces derniers et afficher de meilleures publicités.