Trisil(electronics topic)

A Trisil is an electronic component designed to protect electronic circuits against overvoltage. Unlike a Transil it acts as a crowbar device, switching on when the voltage on it exceeds its breakover voltage.A Trisil is bipolar, behaving the same way in both directions. It is principally a voltage-controlled triac without gate. In 1982, the only manufacturer was Thomson SA. This type of crowbar protector is widely used for protecting telecom equipment from lightning induced transients and induced currents from power lines. Other manufacturers of this type of device include Bourns and Littelfuse. Rather than using the natural breakdown voltage of the device, an extra region is fabricated within the device to form a zener diode. This allows a much tighter control of the breakdown voltage. It is also possible to make gated versions of this type of protector. In this case, the gate is connected to the telecom circuit power supply (via a diode or transistor) so that the device will crowbar if the transient exceeds the power supply voltage. The main advantage of this configuration is that the protection voltage tracks the power supply, so eliminating the problem of selecting a particular breakdown voltage for the protection circuit.

Wibro(electronics seminar topic)

Designed and integrated by the Korean telecom industry as an answer to the drawbacks of speed curbs in the likes of CDMA 1x mobile phones and to increase the flow rate of broadband Internet like the ADSL or Wireless LAN, the technology uses TDD for duplexing, OFDMA for multiple access and 8.75MHz as a channel bandwidth.

As the wibro base stations, provides a dataflow rate of 30 to 50 Mbit/s and also allow the usage of portable internet with in arrange of 1 � 5 Km, obviously the data flow rate, of devices in motion can be in a range of 120 km/hr and about 250 km/hr for wireless lan�s having a slow speed and for mobile phones. This figures were actually higher when compared with the range and bandwidth it offered during the testing of this technology in connection with the APEC summit in Busan in 2005. The main advantage this technology has over the WIMAX standard is its Quality of service (QoS). This QoS gives more reliability for the streaming video content and for other loss-sensitive data. WiBro is quite demanding, in its needs varying from the spectrum use to equipment design, WiMAX leaves much of this up to the equipment provider while supplying enough information to confirm the interoperability between designs.

In Korea, the government by 2001 recognized the advent of this innovative technology by giving a 100 MHz of electromagnetic spectrum in the 2.3 - 2.4 GHz band. By the end of 2004, WiBro Phase 1 was standardized by the TTA of Korea and in late 2005, ITU reflected WiBro as IEEE 802.16e. By June 2006, two major telecom companies in Korea namely the KT and the SKT Two Korean Telco (KT, SKT) began the commercial operations in the country, starting with a charge rate of 30 US$.

Since then, many telecom giants around the world namely the TI (Italia), TVA (Brazil), Omnivision (Venezuela), PORTUS (Croatia), and Arialink (Michigan) have started plans to come out with the commercial operations of the technology.

hydrophone(electronics seminar topic)

A hydrophone is a sound-to-electricity transducer for use in water or other liquids, analogous to a microphone for air. Note that a hydrophone can sometimes also serve as a projector (emitter), but not all hydrophones have this capability, and may be destroyed if used in such a manner.The first device to be called a 'hydrophone' was developed when the technology matured, and used ultrasonic waves, which would provide for higher overall acoustic output, as well as increasing detection. The ultrasonic waves were produced by a mosaic of thin quartz crystals glued between two steel plates, having a resonant frequency of about 150 kHz. Contemporary hydrophones more often use barium titanate, a piezoelectric ceramic material, giving higher sensitivity than quartz. Hydrophones are an important part of the SONAR system used to detect submarines by both surface vessels and other submarines. A large number of hydrophones were used in the building of various fixed location detection networks such as SOSUS.

MeSCoDe

The File Management is a very relevant application in computer field. ‘MeSCoDe’ software focuses on splitting files in a user friendly manner, merging different source files into a single one, compressing a file that can save large extend of memory decompressing compressed files to produce the original file. Compression and decompression are very useful for durable data.

Neuroprosthetics

Neuroprosthetics is an area of neuroscience concerned with neural prostheses, that is, artificial devices used to replace or improve the function of an impaired nervous system. The neuroprosthetic seeing the most widespread use is the cochlear implant, which is in approximately 85,000 people worldwide as of 2005. An early difficulty in the development of neuroprosthetics was reliably locating the electrodes in the brain, originally done by inserting the electrodes with needles and breaking off the needles at the desired depth