Cyber Crime Cyber Security
The crime that involves and uses computer devices and Internet, is known as cybercrime. Cybercrime can be committed against an individual or a group; it can also be committed against…
Superconductivity
Superconductivity is the ability of certain materials to conduct electrical current with no resistance and extremely low losses. This ability to carry large amounts of current can be applied to electric power devices such as motors and generators, and to electricity transmission in power lines. For example, superconductors can carry as much as 100 times the amount of electricity of ordinary copper or aluminum wires of the same size. Scientists had been intrigued with the concept of superconductivity since its discovery in the early 1900s, but the extreme low temperatures the phenomenon required was a barrier to practical and low-cost applications. This all changed in 1986, when a new class of ceramic superconductors was discovered that "superconducted" at higher temperatures. The science of high-temperature superconductivity (HTS) was born, and along with it came the prospect for an elegant technology that promises to "supercharge" the way energy is generated, delivered, and used.
Elements: Information Technology
In of our previous chapters, we discussed the meaning, benefits, and applications of Information Technology; in this chapter, we will discuss, the major elements, i.e., basically the core concept of…
Information Technology
21st century has come to be known as the era of Information Technology; it is the key driver of economic growth of not only a nation, but rather the whole world.…
Science Technology Policy in India
The growth and development of Science and Technology in India is not a decade or a century old activity. There is evidence which shows that it is no less than…
India: Development of Science Technology
For the organized growth and development of Science and Technology in India, different specialized research and development agencies and organization are being set up. Every organization specializes in a particular…
Conduction in Ionic Materials
In ionic materials, the band gap is too large for thermal electron promotion. Cation vacancies allow ionic motion in the direction of an applied electric field, this is referred to as ionic conduction. High temperatures produce more vacancies and higher ionic conductivity. At low temperatures, electrical conduction in insulators is usually along the surface, due to the deposition of moisture that contains impurity ions.
Role of ScienceTechnology In India
Over a period of time, India has progressively and perceptibly paved way for development in the field of Science and Technology. The 21st century in India is apparently marked as the…
Semiconductor Devices
A semiconductor diode is made by the intimate junction of a p-type and an n-typesemiconductor (an n-p junction). Unlike a metal, the intensity of the electrical current that passes through the material depends on the polarity of the applied voltage. If the positive side of abattery is connected to the p-side, a situation called forward bias, a large amount of current can flow since holes and electrons are pushed into the junction region, where they recombine (annihilate). If the polarity of the voltage is flipped, the diode operates under reverse bias. Holes andelectrons are removed from the region of the junction, which therefore becomes depleted of carriers and behaves like an insulator. For this reason, the current is very small under reverse bias. The asymmetric current-voltage characteristics of diodes is used to convert alternating current into direct current. This is called rectification. A p-n-p junction transistor contains two diodes back-to-back. The central region is very thin and is called the base. A small voltage applied to the base has a large effect on the current passing through the transistor, and this can be used to amplify electrical signals (Fig. 19.22). Anothercommon device is the MOSFET transistor where a gate serves the function of the base in a junction transistor. Control of the current through the transistor is by means of the electric field induced by the gate, which is isolated electrically by an oxide layer.
Role of Science Technology in Today’s Life
In today’s world, the role of science and technology is indispensable. We need Science and Technology in every sphere of our life like to treat diseases such as cancer or…
