Wednesday, 5 June 2013

Thermal paste

Thermal paste, also commonly called thermal grease, is a conductive substance used to form a seal between two objects to ensure a consistent and thorough transfer of heat. When installing a new heat sink on a computer, for example, you need to clean off the thermal paste residue from the previous heat sink and then add a thin layer of thermal paste onto the new heat sink before tightening it down. This process creates a seal between the hot body of the CPU and the metal of the heatsink where the heat can migrate more effectively than it could through an air gap.

RESOLUTION


Resolution is a designation of the number of discrete elements an electronic or printed image is comprised of. In the case of displays (both large displays like HDTVs and small displays like those found on smartphones), the resolution is generally described in terms of the horizontal and vertical resolution. An HD monitor or TV, for example, has 1920 pixels running from side to side and 1080 pixels running from top to bottom. Although when discussing computer monitors and displays it is common to refer to the horizontal x vertical pixel count (as in the previously described 1920×1080 monitor), it is more common to talk about smartphone and other small displays in terms of Pixels Per Inch (PPI), which is another way to describe the resolution with an emphasis on how many pixels are in a given area (and thus how sharp and realistic the image is).

When talking about print media, the designation used is Dots Per Inch (DPI), which describes the density of discrete marks made by the printing in a square inch. The higher the DPI the more realistic the image. DPI can range from as low as 50 Dots Per Inch when working with dot-matrix printers to as high as 1800 Dots Per Inch when working with modern laser and photo printers.

The Internet Control Message Protocol (ICMP)


The Internet Control Message Protocol (ICMP) is one of the core networking protocols used to run the Internet. ICMP differs from other transport protocols such as UDP and TCP in that it is not usually used to exchange data between systems but instead used as a diagnostic mechanism. 

Typical ICMP messages indicate network and server states like that a host could not be reached, a router is down, or a service is unavailable. The vast majority of ICMP activity is completely hidden from the end user, although when performing network diagnostics users frequently interact with ICMP via tools like PING and TRACEROUTE. 

RIPPING


Ripping is the process of converting audio or video from its native format to another format for the purposes of reducing the file size and/or re-encoding it to play on a wider variety of devices.

A form of ripping familiar to most people is the process of converting the audio tracks off a music CD into MP3,  AAC, or other portable audio format in order to load the music on an iPod or other portable music player. Any time you pop a CD into your computer, fire up iTunes, and copy the music over to your iTunes library, you’re ripping a CD.
The origins of the usage of ripping in a technological context are unclear. Some sources indicate ripping was intended to indicate that the process ripped off the recording industry by copying albums, while other sources claim it references rip saws, wood working tools used to resize and reshape large pieces of wood much like a CD-to-MP3 ripping tool compresses large albums into MP3 player friendly sizes.




E-MAIL STORM

An email storm is when a very large volume of email messages are sent within a very short span of time. This has the potential to temporarily cripple both the sending and receiving mail servers. Although email storms may be generated by viruses that have gained access to user’s email clients (or even the email server itself), some of the largest mail storms have been generated by human error–typically when a mailing list is improperly configured and a single user is able to reply-all to tens of thousands of other list recipients.