Lithium

Lithium (from Greek: λίθος lithos, "stone") is a chemical element with the symbol Li and atomic number 3. It is a soft, silver-white metal belonging to the alkali metal group of chemical elements. Under standard conditions it is the lightest metal and the least dense solid element. Like all alkali metals, lithium is highly reactive and flammable. For this reason, it is typically stored in mineral oil. When cut open, it exhibits a metallic luster, but contact with moist air corrodes the surface quickly to a dull silvery gray, then black tarnish. Because of its high reactivity, lithium never occurs freely in nature, and instead, only appears in compounds, which are usually ionic. Lithium occurs in a number of pegmatitic minerals, but due to its solubility as an ion, is present in ocean water and is commonly obtained from brines and clays. On a commercial scale, lithium is isolated electrolytically from a mixture of lithium chloride and potassium chloride.

The nuclei of lithium verge on instability, since the two stable lithium isotopes found in nature have among the lowest binding energies per nucleon of all stable nuclides. Because of its relative nuclear instability, lithium is less common in the solar system than 25 of the first 32 chemical elements even though the nuclei are very light in atomic weight. For related reasons, lithium has important links to nuclear physics. The transmutation of lithium atoms to helium in 1932 was the first fully man-made nuclear reaction, and lithium-6 deuteride serves as a fusion fuel in staged thermonuclear weapons.

Lithium Technologies

Lithium Technologies provides social customer experience management software for the enterprise. Headquartered in San Francisco, Lithium has additional offices in London, Austin, Paris, Sydney, Singapore, New York, and Zürich.

Lithium was founded in 2001 as a spin-out from GX Media, which created technologies for professional rankings and tournaments and now hosts a number of popular gaming sites. The company's founders include brothers Lyle Fong and Dennis Fong, who together also founded GX Media, as well as Kirk Yokomizo, John Joh, Nader Alizadeh, Michel Thouati, Michael Yang, and Matt Ayres. The company sells largely to enterprise customers, including HP, Best Buy, Research In Motion, Sony, Comcast, Symantec, and AT&T.

The Lithium Social Customer Experience Management Platform combines online customer community applications such as forums, blogs, innovation management, product reviews, and tribal knowledge bases with the broader social Web and traditional CRM business processes, resulting in a wide range of online customer interaction methods. Lithium's SaaS-based platform delivers products on-demand in a hosted environment rather than as traditional, packaged software. Stemming from its gaming roots, the platform incorporates elaborate rating systems for contributors, with ranks, badges, and “kudos counts.”

Lithium (disambiguation)

Lithium is a chemical element. It may also refer to:

In science

In music

Other

Presence (album)

Presence is the seventh studio album by the English rock band Led Zeppelin, released by Swan Song Records on 31 March 1976. The album was a commercial success, reaching the top of both the British and American album charts, and achieving a triple-platinum certification in the United States, despite receiving mixed reviews from critics and being the slowest-selling studio album by the band (other than the outtake album Coda).

It was written and recorded during a tumultuous time in the band's history, as singer Robert Plant was recuperating from serious injuries he had sustained the previous year in a car accident. Nevertheless, guitarist Jimmy Page describes Presence as the band's "most important" album, proving they would continue and succeed despite their turmoil.

Background

Jimmy Page made the decision to record the album after Robert Plant sustained serious injuries from a car accident on the Greek island of Rhodes on 5 August 1975, which forced the band to cancel a proposed world tour that was due to commence on 23 August. At this point, Led Zeppelin were arguably at the height of their popularity. When he was taken to a Greek hospital after the accident, Plant recalled:

Presence (DC Comics)

The Presence is a fictional representation of God, and is a character in comic books published by DC Comics. The character debuted in More Fun Comics #52 (February 1940), and was created by Jerry Siegel and Bernard Baily.

Publication history

The presence first appears in More Fun Comics #52 as The Voice, the disembodied "Voice of the Presence" who empowers Jim Corrigan as the Spectre. It was created in this story by Jerry Siegel and Bernard Baily.

DC Comics

The religious cosmology of the DC Universe is complex with many pantheons of deities co-existing alongside each other. It involves elements from multiple religions, mythologies, and modern created concepts such as the Endless. It is not always clear how the Abrahamic God fits into this — for example, one particular Wonder Woman storyline by Eric Luke featured the Greek Titans fighting Judeo-Christian angels and Hindu Gods. According to writer Greg Rucka in an interview about his Final Crisis: Revelations miniseries, "The sort of unspoken rule in the DCU is that God sits above all others."

Presence (amplification)

In an amplifier, a presence control boosts the upper mid-range frequencies to make the sounds of voices and instruments with similar tonal ranges seem more "present".

On television production studio's sound desk, there can be several presence controls, for several different, switchable, frequencies. There is a limit to the flexibility of such controls, and they are sometimes insufficient. If the degree of mis-match between microphones is great, simply increasing presence is not enough, and instead a sound engineer will use a graphic equalizer, sometimes several, each connected to an individual sound channel.

Presence controls can also be found on electric guitar amplifiers. The first presence control on a Fender amplifier, for example, appeared in 1954 on the Twin. In 1955 it appeared on the 1/15 Pro-Amp, the 3/10 Bandmaster, the 2/10 Super, and the 4/10 Bassman. The original Fender presence control acted upon the amplifier's negative-feedback loop. As the level of "presence" was increased, so more and more of the higher frequencies in the negative-feedback loop were dumped to ground, leaving the low and mid-range frequencies. Increasing the presence resulted in there being less and less negative feedback on high frequencies. The effect varied according to amplitude.