Ether

Ethers (/ˈiːθər/) are a class of organic compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups—of general formula R–O–R'. These ethers can again be classified into two varieties, if the alkyl groups are the same on both sides of the oxygen atom then it is a simple or symmetrical ether. Whereas if they are different the ethers are called mixed or unsymmetrical ethers A typical example is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether" (CH₃-CH₂-O-CH₂-CH₃). Ethers are common in organic chemistry and pervasive in biochemistry, as they are common linkages in carbohydrates and lignin.

Structure and bonding

Ethers feature C-O-C linkage defined by a bond angle of about 110° and C-O distances of about 140 pm. The barrier to rotation about the C-O bonds is low. The bonding of oxygen in ethers, alcohols, and water is similar. In the language of valence bond theory, the hybridization at oxygen is sp³.

Oxygen is more electronegative than carbon, thus the hydrogens alpha to ethers are more acidic than in simple hydrocarbons. They are far less acidic than hydrogens alpha to carbonyl groups (such as in ketones or aldehydes), however.

Music video

A music video or song video is a short film integrating a song and imagery, produced for promotional or artistic purposes. Modern music videos are primarily made and used as a marketing device intended to promote the sale of music recordings. There are also cases where songs are used in tie in marketing campaigns that allow them to become more than just a song. Tie ins and merchandising could be used in toys are marketing campaigns for food and other products. Although the origins of music videos date back to musical short films that first appeared in the 1920s, they came into prominence in the 1980s when MTV based their format around the medium. Prior to the 1980s, these works were described by various terms including "illustrated song", "filmed insert", "promotional (promo) film", "promotional clip", "promotional video", "song video", "song clip" or "film clip". Since the creation and increased popularity of YouTube, mainstream artists now promote new music videos by releasing trailers of short promos on the site for their upcoming song and music video. Consequentially, YouTube has been converted into a social media platform for celebrities and artists to market themselves to their fans and audiences.

24 Oras

24 Oras (24 Hours) is the flagship national network news broadcast of GMA Network. It is the nightly national newscast which airs in the Philippines on GMA and worldwide via GMA Pinoy TV. It is aired every weeknights from 6:30 PM to 7:45 PM, and every Saturdays and Sundays from 5:30 PM to 6:00 PM (PST). The newscast can be heard on radio through Super Radyo DZBB 594 in Mega Manila and several of its regional Super Radyo stations nationwide (Super Radyo 909 Palawan, Super Radyo 1323 Iloilo, Super Radyo 999 Cebu and Super Radyo 1125 Davao).

History

2004-2014

24 Oras premiered on March 15, 2004 at 6:15pm, replacing Frontpage: Ulat ni Mel Tiangco as the network's answer to longest-running newscast TV Patrol. Frontpage anchor Mel Tiangco was joined by Saksi's Mike Enriquez, rejoining them in one newscast since they co-anchored Saksi from 1996 to 1998. Special weekend editions are also being aired when it deemed necessary (See below). The show, meanwhile, transferred its timeslot from 6:15pm to 6:30pm, it was currently extended to 90 minutes.