Monday, March 24, 2008


TELNET (TELecommunication NETwork) is a network protocol used on the Internet or local area network (LAN) connections. It was developed in 1969 beginning with RFC 15 and standardized as IETF STD 8, one of the first Internet standards.

The term telnet also refers to software which implements the client part of the protocol. TELNET clients have been available on most Unix systems for many years and are available for virtually all platforms. Most network equipment and OSs with a TCP/IP stack support some kind of TELNET service server for their remote configuration (including ones based on Windows NT). Because of security issues with TELNET, its use has waned as it is replaced by the use of SSH for remote access.

Monday, March 17, 2008

Hybrid Locomotive

Hybrid Locomotive is a locomotive or multiple unit train that uses an on-board rechargeable energy storage system (RESS) (battery or ultracapacitors) and a fueled power source for propulsion.

Hybrid trains typically are powered either by fuel cell technology or the more conventional diesel-electric hybrid which reduces fuel consumption through regenerative braking and switching off the hydrocarbon engine when idling or stationary (as used in automobiles such as the Toyota Prius).

Energy used by train operations makes up approximately 70% of all energy consumed by railroad companies, so reduction of this not only provides environmental benefits but economic advantages as well.

Sunday, March 09, 2008


Polymer light-emitting diodes (PLED), also Light-Emitting Polymers (LEP) and Flexible OLED (FOLED), involve an electroluminescent conductive polymer that emits light when connected to an external voltage source. They are used as a thin film for full-spectrum color displays and require a relatively small amount of power for the light produced. No vacuum is required, and the emissive materials can be applied on the substrate by a technique derived from commercial inkjet printing. The substrate used can be flexible, such as PET. Thus, flexible PLED displays may be produced inexpensively.

Tuesday, March 04, 2008

Computational chemistry

Computational chemistry is a branch of chemistry that uses computers to assist in solving chemical problems. It uses the results of theoretical chemistry, incorporated into efficient computer programs, to calculate the structures and properties of molecules and solids. While its results normally complement the information obtained by chemical experiments, it can in some cases predict hitherto unobserved chemical phenomena. It is widely used in the design of new drugs and materials.

Examples of such properties are structure (i.e. the expected positions of the constituent atoms), absolute and relative (interaction) energies, electronic charge distributions, dipoles and higher multipole moments, vibrational frequencies, reactivity or other spectroscopic quantities, and cross sections for collision with other particles.